Irregularly occurring "unknown error" : "An unknown error occurred in the remote end while processing the command."

[kateBiro]

Looking for help/ideas:

Using appium and WinAppDriver to automate tests for 2 different native Windows apps. Appium server and apps installed and run in the same vm, but by different users.

This error is occurring some of the time, for some method inconsistently, and only for certain users.

As developer, I have been unable to duplicate the error except by disconnecting from the vm the test is running on. No matter the vm or even if I log in as a different user (yes, the one who experiences the errors) I cannot seem to get this error to occur.

We have seen the error as early as January, but have noticed it with great regularity (occurs typically once per run of ~80 test cases).

The session will be created and some commands will execute and then we see the WindowsDriver return a 500 error. Sometimes this is on a click, sometimes on a screenshot. I attempted to debug by allowing the program to continue after a failed screenshot, however any further commands to Webdriver will return a 500 unknown error as well.

I have engaged my network team to see if we are experiencing periodic outages or other issue for the other users, but haven't turned up anything useful yet.

I've also tried reinstalling appium and WindowsDriver as well as using different versions.

We recently build an entirely new server (Windows Server 2019) to troubleshoot and have the same errors occurring.

Here is a snip of the appium log at the point of error:

2025-04-09 13:18:49:416 [6dd24756][HTTP] --> GET /wd/hub/session/6dd24756-e324-4bc3-a7c9-5381ea94a132/element/7.9200.3531486/enabled {}
2025-04-09 13:18:49:416 [6dd24756][WindowsDriver@9b4f] Driver proxy active, passing request on via HTTP proxy
2025-04-09 13:18:49:419 [6dd24756][WindowsDriver@9b4f] Replacing sessionId 8B4B75C2-F829-4333-BCE3-A1AAFF35F53D with 6dd24756-e324-4bc3-a7c9-5381ea94a132
2025-04-09 13:18:49:420 [6dd24756][HTTP] <-- GET /wd/hub/session/6dd24756-e324-4bc3-a7c9-5381ea94a132/element/7.9200.3531486/enabled 200 4 ms - 65
2025-04-09 13:18:49:422 [6dd24756][HTTP] --> POST /wd/hub/session/6dd24756-e324-4bc3-a7c9-5381ea94a132/element/7.9200.3531486/click {}
2025-04-09 13:18:49:422 [6dd24756][WindowsDriver@9b4f] Driver proxy active, passing request on via HTTP proxy
2025-04-09 13:18:51:474 [6dd24756][WindowsDriver@9b4f] Got response with status 500: {"status":13,"value":{"error":"unknown error","message":"An unknown error occurred in the remote end while processing the command."}}
2025-04-09 13:18:51:475 [6dd24756][HTTP] <-- POST /wd/hub/session/6dd24756-e324-4bc3-a7c9-5381ea94a132/element/7.9200.3531486/click 500 2053 ms - 843

Any ideas appreciated!

[anunay1]

This error happens if the server has gone bad, even I could not figure out why???. As a work around, I start the winappdriver.exe before every test and kill it after the test ends.

The pattern of this error is also not known to reproduce it. it can happen anytime.