We were using MTM 2015 and TFS 2015. While trying to run the Coded UI automation with vNext build started encountering an issue
The build directory of the test run either does not exist or access permission is required
Started digging deep and then came across this link msdn.
At the end if you see Q and A:
Q: Can I use vNext builds to run automated tests in lab environments?
A: Currently only XAML builds are supported with automated testing. Microsoft Test Manager does not support Team Foundation 2015 build (also called Build vNext). Microsoft Test Manager will allow you to associate a vNext build with your Test Plan, but when you try to trigger an automated test using a lab environment, your test run will fail and the error log will show you the following message - which may be misleading.
The build directory of the test run either does not exist or access permission is required
Question is does MTM 2017 supports Coded UI automation execution with vNext build? If not when can we expect this MTM + vNext build work without any issues?
No. That feature will not be added to MTM; MTM and Lab Management are deprecated in favor of the full web-based test hub experience. When you run MTM 2017, it even pops up a warning telling you this. It's also worth noting that Coded UI is deprecated in favor of Selenium for web browser-based testing and Appium for desktop testing. Although all of these tools are still supported, they are no longer receiving feature updates.
You can run test automation from release definitions in TFS 2017 and 2018.