Revit cannot run the external application

[david.faircloth]

One of my users got a Revit cannot run external application error messages yesterday. What makes this interesting is when opening Revit the message pops up 16 times all for something different. 

External Tool Failure.

We have tried a clean reinstall but still get the same messages. 

[MichaelDol]

There may be a problem with the operating system or the hard drive.

[david.faircloth]

Just providing an update.

Support got with us and after running some test's we determined that running version 21.1.7 is causing the issue. Not sure why as we have been on 21.1.7 since it came out. We were able to roll back to the previous version which I believe is 21.1 and everything is working properly. If we try and update to 21.1.7 the problems come back.