How to remove build tasks

[pabrams]

I'm on TFS 2017 Update 3

1. Remove extension using UI (serverUrl/_gallery/manage -> Remove... )

2. Upload the same extension using the UI

3. Install the extension to a collection

4. Receive this error from the UI:
   
   Changing the task version inside the .vsix is not a good solution, so I want to remove the task, instead, but tfx-cli claims it's not there:

5. Try to delete the build task definition:
   C:\somefolder>tfx build tasks delete --task-id "50759521-9C5E-4F40-9AE7-8F9876BA9439" --service-url "http://{same string as blacked-out in above screenshot}:8080/tfs/{same collection string as blacked out in above screenshot}"
   TFS Cross Platform Command Line Interface v0.5.10
   Copyright Microsoft Corporation
   error: Error: Failed Request: Not Found(404) - No task definition found matching id 50759521-9c5e-4f40-9ae7-8f9876ba9439

6. Tried it without the collection part of the --service-url; same result

I'm using tfx-cli 0.5.10 because I think that's the last version that worked for us. After that, several breaking changes were introduced.

[pabrams]

Closing this and replacing with similar issue for latest version of tfx-cli