Error when both VS2017 and VS2019 are installed on same server

[RoyLofthus]

The task started to fail after VS2019 was installed on the build-agent, By looking at the debug-output, it looks like the Get-VsPath method returns paths to both versions, instead of just the Latest. We've tried to specify a specific version, but with same result. Attached is a screenshot of the debug-output

[mmajcica]

Seems that one of the cmdlets in certain cases is returning an array. This I haven't thought to be possible. I made a quick fix, would it be possible for you to test it?
https://github.com/mmajcica/DevEnvBuild/releases/tag/2.0.4

If this works, I will publish it right away.

[mmajcica]

@RoyLofthus please ignore my last comment. I checked your logs and seems you were pointing to a specific version. This shouldn't be the case. It is late at my place right now, I'll take a better look at this tomorrow.

[dorChuck]

Was this issue resolved? Yesterday I was receiving the same error message:
##[error]Cannot process argument transformation on parameter 'FileName'. Cannot convert value to type System.String.
I did not have diagnostics logs turned so I can't be sure if all the errors matched the ones received by @RoyLofthus .

After some research, I changed the task version from 1.* to 2.* to have VS 2019 compatibility. I was previously using it for VS 2017 solutions. I believe I got past this error by deleting the DevEnv task and adding a new one. I think I also had the solution file name in the project field after the version change. Which caused other errors.

[Pashanaz]

[Pashanaz]

[Metarract]

also ran into this issue - but for ours, the problem stemmed from having both VS professional and VS enterprise on the same machine

[Ezeckiel2517]

Also get the same error. This is cause by the function Get-VSPath that fails to narrow down the path of vs2019.
The code below in incorrect because it filtered all instance version 16 and UP.

if ($Version -eq "16.0" -and ($instance = Get-VSSetupInstance | Select-VSSetupInstance -Version '[16.0,)') -and $instance.installationPath) { return $instance.installationPath }

The correct filter should be
Get-VSSetupInstance | Select-VSSetupInstance -Version '[16.0,17.0)'