1page.title=Troubleshooting 2parent.title=FAQs, Tips, and How-to 3parent.link=index.html 4@jd:body 5 6 7<p>Here are some tips and tricks for common Android errors. Don't forget to use the 8 ddms logcat capability to get a deeper view when errors occur. See <a href="{@docRoot}guide/developing/debug-tasks.html">Debugging</a> for more debugging tips. </p> 9<ul> 10 <li><a href="#installeclipsecomponents">ADT Installation Error: "requires plug-in org.eclipse.wst.sse.ui".</a></li> 11 <li><a href="#nodevice">ADB reports "no device" when an emulator is running</a></li> 12 <li><a href="#noapp">My new application/activity isn't showing up in the device application 13 list </a></li> 14 <li><a href="#noupdate">I updated my app, but the updates don't seem to be showing up on 15 the device</a></li> 16 <li><a href="#layout_wilih">I'm getting a "Binary XML file line #2: You must supply a layout_wilih 17 attribute" error when I start an application</a></li> 18 <li><a href="#permission">My request to (<em>make a call, catch an incoming SMS, receive 19 a notification, send an intent to an Android application</em>) is being 20 ignored</a></li> 21 <li><a href="#build">Help! My project won't build in Eclipse</a></li> 22 <li><a href="#eclipse">Eclipse isn't talking to the emulator</a></li> 23 <li><a href="#majorminor">When I go to preferences in Eclipse and select "Android", I get the following error message: Unsupported major.minor version 49.0.</a></li> 24 <li><a href="#apidemosreinstall">I can't install ApiDemos apps in my IDE because of a signing error</a></li> 25 <li><a href="#signingcalendar">I can't compile my app because the build tools generated an expired debug certificate</a></li> 26</ul> 27 28<a name="installeclipsecomponents" id="installeclipsecomponents"></a><h2>ADT Installation Error: "requires plug-in org.eclipse.wst.sse.ui".</h2> 29<p> 30The "Android Editors" feature of the ADT Plugin requires specific Eclipse components, such as WST. If you 31encounter this error message during ADT installation, you need to install the 32required Eclipse components and then try the ADT installation again. Follow the steps below to install the required components for the 33Android Editors feature, based on the version of Eclipse that you are using.</p> 34 35<table style="font-size:100%"> 36<tr><th>Eclipse 3.3 (Europa)</th><th>Eclipse 3.4 (Ganymede)</th></tr> 37<tr> 38<td width="50%"> 39<ol> 40<li>From the dialog where you select the <strong>Update sites to visit</strong>, select the checkboxes for both the 41ADT site, and the Callisto/Europa/Ganymede Discovery Site (you may want to 42check <strong>Automatically select mirrors</strong> at the bottom).</li> 43<li>Click <strong>Finish</strong>.</li> 44<li>In the <strong>Next</strong> dialog, select the Android Plugins.</li> 45<li>Now, expand the tree item of the discovery site. It seems that if you 46don't do it, it doesn't load the content of the discovery site.</li> 47<li>On the right, click <strong>Select required</strong>. This will select all the components 48that are required to install the Android plugin (wst, emf, etc...).</li> 49<li>Click <strong>Next</strong>, accept the agreement, click <strong>Install All</strong>, and restart Eclipse.</li> 50</ol> 51</td> 52<td> 53<ol> 54 <li>Select <strong>Help</strong> > <strong>Software Updates...</strong></li> 55 <li>Select the <strong>Installed Software</strong> tab.</li> 56 <li>Click <strong>Update...</strong></li> 57 <li>If an update for ADT is available, select it and click <strong>Finish</strong>.</li> 58</ol> 59</td> 60</tr> 61</table> 62 63 64</p> 65<a name="nodevice"></a><h2>ADB reports "no device" when an emulator is running</h2> 66 <p>Try restarting adb by stopping it (<code>adb 67 kill-server</code>) then any other adb command to restart it.</p> 68 69<a name="noapp"></a><h2>My new application/activity isn't showing up in the 70 applications list </h2> 71<ul> 72 <li>You often must restart your device or emulator before a new activity shows 73 up in the applications list. This is particularly true when it is a completely 74 new application with a new AndroidManifest.xml file.</li> 75 <li>If this is for a new activity in an existing AndroidManifest.xml file, did 76 you include an <code><activity></code> tag for your app (or a <code><service></code> tag 77 for a service, or a <code><receiver></code> tag for a receiver, etc.)? </li> 78 <li>Make sure that your AndroidManifest.xml file is valid. Errors in attribute 79 values, such as the <em>value </em> attribute in <code><action <em>value</em>="<em><something></em>"></code> 80 will often not be caught by compilers, but will prevent your application 81 from being displayed because the intent filter will not be matched. Extra 82 spaces or other characters can often sneak into these strings.</li> 83 <li>Did you send your .apk file to the device (<a href="{@docRoot}guide/developing/tools/adb.html#move">adb install</a>)?</li> 84 <li>Run logcat on your device (<code>adb logcat</code>) 85 and then install your .apk file. Check the logcat output to see whether the 86 application is being installed and recognized properly. Here's sample output 87 from a successful installation: 88<pre>I/FileObserver( 414): *** onEvent wfd: 3 mask: 8 path: MyRSSReader.apk 89D/PackageManager( 414): Scanning package: /data/app/MyRSSReader.apk 90D/PackageManager( 414): Adding package com.example.codelab.rssexample 91D/PackageManager( 414): Registered content provider: my_rss_item, className = com.example.codelab.rssexample.RssContentProvider, isSyncable = false 92D/PackageManager( 414): Providers: com.example.codelab.rssexample.RssContentProvider 93D/PackageManager( 414): Activities: com.example.codelab.rssexample.MyRssReader com.example.codelab.rssexample.MyRssReader2 </pre> 94 </li> 95 <li>If logcat shows that the package manager is having problems loading the manifest 96 file, force your manifest to be recompiled by adding a space in the file and 97 compiling it.</li> 98</ul> 99<a name="noupdate"></a><h2>I updated my app, but the updates don't seem to be showing up on the device</h2> 100 <p>Did you remember to send your .apk file to the device (<a href="{@docRoot}guide/developing/tools/adb.html#move">adb 101 install</a>)?</p> 102 103<a name="layout_wilih"></a><h2>I'm getting a "Binary XML file line #2: You must supply a layout_wilih 104 attribute" error 105 when I start an application (but I declare a layout_wilih attribute <em>right 106 there!!!</em>)</h2> 107<ul> 108 <li>Make sure that the SDK you are building with is the same version as the Android 109 OS that you are running on. </li> 110 <li>Make sure that you're calling setContentView() early in your onCreate() method. 111 Calling other methods, such as setListAdapter() before calling setContentView() 112 can sometimes create odd errors when Android tries to access screen elements 113 that haven't been set before.</li> 114</ul> 115<a name="permission"></a><h2>My request to (<em>make a call, catch an incoming SMS, 116receive a notification, send an intent to an Android application</em>) is being 117ignored</h2> 118 <p>You might not have permission (or might not have requested permission) to 119 call this activity or receive this intent. Many standard Android activities, 120 such as making a call, have a permission assigned to it to prevent arbitrary 121 applications from sending or receiving requests. See <a 122 href="{@docRoot}guide/topics/security/security.html">Security and 123 Permissions</a> for more information on permissions, and 124 {@link android.Manifest.permission Manifest.permission} for a list of 125 standard permissions supported by the Android platform. 126</p> 127<a name="build"></a><h2>Help! My project won't build in Eclipse</h2> 128<p>If your project doesn't build, you may notice symptoms such as new 129resources added in the <code>res/</code> sub-folders not showing up in the R class, 130the emulator not being started, not being able to run the application, or even seeming to run an old version of the application.</p> 131<p>To troubleshoot these types of problems, first try:</p> 132<ol> 133 <li>Switch to the DDMS view in Eclipse (if you don't already have it open): 134 <ol type="a"> 135 <li>From the menu select <code>Window > Open Perspective > Other</code></li> 136 <li>Select DDMS from the list and hit OK</li> 137 </ol> 138 </li> 139 <li>In the Devices panel (top right panel by default), click on the down triangle 140 to bring up the panel menu</li> 141 <li>Select <code>Reset ADB</code> from the menu, and then try running the 142 application again</li> 143</ol> 144<p>If the above still doesn't work, you can try these steps:</p> 145<ol> 146 <li> 147 Check the console and problems tabs at the bottom of the Eclipse UI 148 </li> 149 <li> 150 If there are problems listed in either place, they should give you a clue 151 what is wrong 152 </li> 153 <li> 154 If you aren't sure if the problems are fresh or stale, clear the console 155 with a right click > Clear, then clean the project 156 </li> 157 <li> 158 To clean the project (a good idea with any kind of build error), select 159 Project > Clean from the eclipse main menu, then select the project you 160 are working on (or clean all) 161 </li> 162</ol> 163<a name="eclipse"></a><h2>Eclipse isn't talking to the emulator</h2> 164<p>When communication doesn't seem to be happening between Eclipse and the emulator, symptoms can include: nothing happening when you press run, the emulator hanging waiting 165for a debugger to connect, or errors that Eclipse reports about not being able 166to find the emulator or shell. By far the most common symptom is that when you press run, the emulator starts (or 167is already running), but the application doesn't start.</p> 168<p> 169You may find any of these steps will fix the problem and with practice you 170probably can figure out which one you need to do for your particular issue, but 171to start with, the safest option is to run through all of them in order:</p> 172<ol> 173 <li> 174 Quit the emulator if it is running 175 </li> 176 <li> 177 Check that any emulator processes are killed (sometimes they can hang, use ps on unix or mac, or task manager in the process view on 178 windows). 179 </li> 180 <li> 181 Quit Eclipse 182 </li> 183 <li> 184 From the command line, type: 185<pre>adb kill-server </pre> 186 </li> 187 <li> 188 Start Eclipse and try again 189 </li> 190</ol> 191 192<a name="majorminor"></a><h2>When I go to preferences in Eclipse and select "Android", I get the following error message: Unsupported major.minor version 49.0.</h2> 193<p>This error is displayed if you are using an older version of the JDK. Please make sure you are using JDK version 5 or 6.</p> 194 195<h2 id="apidemosreinstall">I can't install ApiDemos apps in my IDE because of a signing error</a></h2> 196 197<p>The Android system requires that all applications be signed, as described in 198 <a href="{@docRoot}guide/publishing/app-signing.html">Signing Your Applications</a>. The ApiDemos 199applications included with the SDK are preinstalled on the emulator and for that reason have been 200compiled and signed with a private key.</p> 201 202If you want to modify or run one of the ApiDemos apps from Eclipse/ADT or other IDE, you can do so 203so only after you uninstall the <em>preinstalled</em> version of the app from the emulator. If 204you try to run an ApiDemos apps from your IDE without removing the preinstalled version first, 205you will get errors similar to: </p> 206 207<pre>[2008-08-13 15:14:15 - ApiDemos] Re-installation failed due to different application signatures. 208[2008-08-13 15:14:15 - ApiDemos] You must perform a full uninstall of the application. WARNING: ...This will remove the application data! 209[2008-08-13 15:14:15 - ApiDemos] Please execute 'adb uninstall com.android.samples' in a shell.</pre> 210 211<p>The error occurs because, in this case, you are attempting to install another copy of ApiDemos 212onto the emulator, a copy that is signed with a different certificate (the Android IDE tools will 213have signed the app with a debug certificate, where the existing version was already signed with 214a private certificate). The system does not allow this type of reinstallation. </p> 215 216<p>To resolve the issue, you need to fully uninstall the preinstalled and then reinstall it using 217the adb tool. Here's how to do that:</p> 218 219<ol> 220 <li>In a terminal, change to the tools directory of the SDK.</li> 221 <li>If no emulator instance is running, start an emulator using using the command <code>emulator &</code>.</li> 222 <li>Uninstall the preinstalled app using the command <code>adb uninstall com.android.samples</code>.</li> 223 <li>Reinstall the app using the command <code>adb install <path to the ApiDemos.apk></code>. If you are 224 working in Eclipse/ADT, you can just compile and run the app in the normal way. </li> 225</ol> 226 227<p>Note that if multiple emulator instances are running, you need to direct your uninstall/install 228commands to the emulator instance that you are targeting. To do that you can add the 229<code>-s <serialNumber></code> to the command, for example: </p> 230 231<pre>adb -s emulator-5556 install</pre> 232 233<p>For more information about adb, see the <a href="{@docRoot}guide/developing/tools/adb.html">Android Debug Bridge</a> 234documentation.</p> 235 236 237<h2 id="signingcalendar">I can't compile my app because the build tools generated an expired debug certificate</h2> 238 239<p>If your development machine uses a locale that has a non-Gregorian calendar, you may encounter problems when first trying to compile and run your application. Specifically, you may find that the Android build tools won't compile your application because the debug key is expired. </p> 240 241<p>The problem occurs because the Keytool utility — included in the JDK and used by the Android build tools — fails to properly handle non-Gregorian locales and may create validity dates that are in the past. That is, it may generate a debug key that is already expired, which results in the compile error.</p> 242 243<p>If you encounter this problem, follow these steps to work around it: </p> 244 245<ol> 246<li>First, delete the debug keystore/key already generated by the Android build tools. Specifically, delete the <code>debug.keystore</code> file. On Linux/Mac OSX, the file is stored in <code>~/.android</code>. On Windows XP, the file is stored in <code> 247C:\Documents and Settings\<user>\.android</code>. On Windows Vista, the file is stored in <code> 248C:\Users\<user>\.android</code></li> 249<li>Next, you can either 250<ul> 251<li>Temporarily change your development machine's locale (date and time) to one that uses a Gregorian calendar, for example, United States. Once the locale is changed, use the Android build tools to compile and install your app. The build tools will regenerate a new keystore and debug key with valid dates. Once the new debug key is generated, you can reset your development machine to the original locale. </li> 252<li>Alternatively, if you do not want to change your machine's locale settings, you can generate the keystore/key on any machine using the Gregorian calendar, then copy the <code>debug.keystore</code> file from that computer to the proper location on your development machine. </li> 253</ul> 254</li> 255</ol> 256 257<p>This problem has been verified on Windows and may apply to other platforms. </p> 258 259<p>For general information about signing Android applications, see 260<a href="{@docRoot}guide/publishing/app-signing.html">Signing Your Applications</a>. </p> 261 262