Aug 02, 2019 - 08:32 AM
I found the solution to this issue later on the same day and would like to share it with the community. It looks like that this error can occur if PSCAD is unable to access the file identified in the error message. If this wasn't an issue before, it is possible that a new group policy is pushed onto a machine which causes the issue.
Solution: Whitelisting the path "C:\Program Files (x86)\PSCAD46\bin\win\tline.exe" in the protection software/firewall and restarting the machine solved the problem.
I hope this helps.
Source: PSCAD support team