File Error - Illegal Name

When rendering a project in FCP7 I keep on getting a error saying "File Error - Illegal Name" can anyone help me out? I cannot figure out the issue, I tried changing the sequence name to something different but it still appears, I also tried restarting my computer.

Go to the, I'm doing this from memory, Tools menu I think. Find the Render Manager. This will bring up the Render Manager window. There is a column call Remove I believe, and you can click in that column to select which render files to delete. Then re-launch FCP 7. The error is talking about the names of hidden render files, not your sequence or project name. Normally caused by corrupted render files.