# Interesting PROS Issue

Does anyone know what would cause this and/or how to fix it? Someone within my organization is getting this when trying to run

``````
pros mu

``````

.

``````
pros

``````

and

``````
pros --version

``````

(2.5.1) work just fine.

My best guess from the stack trace is that the

``````
PROS_TOOLCHAIN

``````

environment variable wasn’t set on installation.

You can quickly open the environment variables editor by pressing Win+R and entering

``````
rundll32 sysdm.cpl,EditEnvironmentVariables

``````

If you used the Windows installers, you’ll likely want to set it to C:\Program Files\PROS\toolchain (might be under C:\Program Files (x86) depending on your system).

If it’s already set, restart the program. If you’re still having issues, open up that folder and verify that C:\Program Files\PROS\toolchain\bin\make.exe exists.

Hope this helps.

I see. I’ll try it tomorrow and update this thread accordingly.

I would guess that the user account used for the installation being a Standard one (not Administrator) might have caused the problem; the PROS installer might not have requested elevation through UAC correctly for setting the environment variable. Hopefully this can be fixed for PROS 3 if it turns out to be the case.