1# Driver Error Codes 2<!--Kit: Driver Development Kit--> 3<!--Subsystem: Driver--> 4<!--Owner: @lixinsheng2--> 5<!--Designer: @w00373942--> 6<!--Tester: @dong-dongzhen--> 7<!--Adviser: @w_Machine_cc--> 8 9> **NOTE** 10> 11> This topic describes only module-specific error codes. For details about universal error codes, see [Universal Error Codes](../errorcode-universal.md). 12 13## 22900001 ExternalDeviceManager Service Exception or busType Parameter Error 14 15**Error Message** 16 17ExternalDeviceManager service exception or busType parameter error. 18 19**Description** 20 21This error code is reported if the ExternalDeviceManager service is abnormal or the **busType** parameter is invalid. 22 23**Possible Causes** 24 251. The product type is incorrect. Only 2-in-1 and tablet products are supported. 262. An internal communication error occurs in the ExternalDeviceManager service. 273. The **busType** parameter is not properly set. 28 29**Solution** 30 311. Change the product type. 322. Restart the device<!--RP1-->. You can also submit an [issue](https://gitee.com/openharmony/drivers_external_device_manager/issues/new) online.<!--RP1End--> 333. Query the supported bus types using [deviceManager.BusType](js-apis-driver-deviceManager.md#bustype). 34 35## 26300001 ExternalDeviceManager Service Exception 36 37**Error Message** 38 39ExternalDeviceManager service exception. 40 41**Description** 42 43This error code is reported if the ExternalDeviceManager service is abnormal. 44 45**Possible Causes** 46 471. The product type is incorrect. Only 2-in-1 and tablet products are supported. 482. An internal communication error occurs in the ExternalDeviceManager service. 49 50**Solution** 51 521. Change the product type. 532. Restart the device<!--RP1-->. You can also submit an [issue](https://gitee.com/openharmony/drivers_external_device_manager/issues/new) online.<!--RP1End--> 54 55## 26300002 Binding Driver Client to Driver Server Failed 56 57**Error Message** 58 59The driver service does not allow any client to bind. 60 61**Description** 62 63This error code is reported if a driver client is prohibited from binding a driver server. 64 65**Possible Causes** 66 67An incorrect value is set for `ohos.permission.ACCESS_DDK_ALLOWED` in the `metadata` attribute of the `extensionAbilities` structure whose `type` is `driver`. 68 69**Solution** 70 71In the source code project of the non-standard peripheral driver, open the `entry/src/main/module.json5` file, and assign the value `true` to `ohos.permission.ACCESS_DDK_ALLOWED` in the `metadata` attribute of the `extensionAbilities` structure whose `type` is `driver`. 72 73## 26300003 Driver Client Not Bound to Any Driver Server 74 75**Error Message** 76 77There is no binding relationship. 78 79**Description** 80 81This error code is reported if a driver client is not bound to any driver server. 82 83**Possible Causes** 84 85`unbindDriverWithDeviceId` is called when `bindDriverWithDeviceId` is not called or fails to be called. 86 87**Solution** 88 89Call `unbindDriverWithDeviceId` only after `bindDriverWithDeviceId` is called successfully. 90