Since a few weeks, when I edit a file in a PSSession in ISE I get this error message when I save the modifications:

Saving file: C:\path\file.ps1 in the remote session has failed with error: Exception has been thrown by the target of an invocation..

Not sure there is a link, but this problem appeared around the moment when this post has been published.

https://devblogs.microsoft.com/powershell/windows-security-change-affecting-powershell/