If it worked before, and doesn't work after running it, the executable or any other files (e.g. dll's) you used have been corrupted.

Assuming you're using windows; here's your checklist.

---EDIT---
One thing came to mind suddenly, try clearing the first few replays (alphabethically) from your replays folder, also try clearing your autosave folder.
---EDIT---

Click on show details on the error message, post it here.

Run a scandisk / defragmentation, if defragmentation is high, stop here, reply.

Run a spy/adware check. Use spybot S&D. It's the best out of them.

Run another virus check with free AV, Avast! If you already do not use it. (But for love of invisible men, shut down your primary antivirus off first for the duration of the scan.)
It's a possibility your current Anti-Virus has been compromised or is lacking the info on the possible virus, uninstall Avast! after this operation, running 2 antiviruses at the same time is not good.

If all the above fails, dxdiag in here, please If you don't know how to do that, post here.