If you've done all that, it confirms that the screen saver file is not likely corrupt. Several things could be at fault and it'll be tricky knowing which is causing the problem. Here are some possible culprits:
1)..Software conflict. You may have other software installed that is conflicting with the screensaver. Maybe it is writing to memory that doesn't belong to it, maybe belonging to the screensaver, causing it to crash.
2)..Bad memory. It's possible to have a bad memory chip which could cause problems, but you would probably be seeing this beyond just the operation of this screensaver.
3)..Antivirus-related conflict. You may have antivirus software running that is trying to monitor/close the screensaver. Rare, but it's possible.
4)..Think back to the time when the screensaver was working fine and try to determine what software/hardware updates/additions you have added since then.
Here's something to try:
Start your system in safe mode (or normally, but close/shut down almost everything running), to guarantee nothing could possibly conflict, then start the screensaver. From your screenshot, it looks like you have a lot of customization (custom desktop, etc), which could easily be an issue with a screensaver.