Unable to compile custom assembly error

As prompted when logging into my desktop app, I tried to move off of one drive. Now my app is completely messed up. I have reinstalled several times (I am no longer connected to one drive). I get around 40 error messages I need to click through before I’m able to log on. Now I can not add on any more scripts, until the other program errors are fixed. I am not a programmer. Please advise.