1# UiTest Error Codes 2 3> **NOTE** 4> 5> This topic describes only module-specific error codes. For details about universal error codes, see [Universal Error Codes](errorcode-universal.md). 6 7## 17000001 Initialization Failure 8 9**Error Message** 10 11Initialize failed. 12 13**Description** 14 15This error code is reported when the framework fails to be initialized. 16 17**Possible Causes** 18 19The accessibility service cannot be accessed. 20 21**Solution** 22 23Run the **param set persist.ace.testmode.enabled 1** command and restart the device. 24 25## 17000002 Unable to Call the API 26**Error Message** 27 28API does not allow calling concurrently. 29 30**Description** 31 32This error code is reported when the API fails to be called. 33 34**Possible Causes** 35 36The API was not called using **await**. 37 38**Solution** 39 40Check test cases and make sure asynchronous APIs are called using **await**. 41 42## 17000003 Assertion Failure 43**Error Message** 44 45Component existence assertion failed. 46 47**Description** 48 49This error code is reported when the user assertion fails. 50 51**Possible Causes** 52 53The component that the user asserts to exist does not exist. 54 55**Solution** 56 57Check the existence of the component that is asserted to exist. 58 59## 17000004 Target Component/Window Lost 60**Error Message** 61 62Component lost/UiWindow lost. 63 64**Description** 65 66This error code is reported when the target component or window is lost and cannot be operated. 67 68**Possible Causes** 69 70After the target component or window is obtained, the page changes. As a result, the target component or window is lost. 71 72**Solution** 73 74Check whether the loss is caused by page changes. 75 76## 17000005 Operation Not Supported 77**Error Message** 78 79This operation is not supported. 80 81**Description** 82 83This error code is reported when the performed operation is not supported by the UI object. 84 85**Possible Causes** 86 87The component or window attribute does not support the performed operation. 88 89**Solution** 90 91Make sure the operation to perform is supported by the component or window attribute. 92