Have you tried renaming it in the repo browser? This works without creating a file, so windows file name restrictions should not be a problem.
You received this message because you are subscribed to the Google Groups "TortoiseSVN" group.
To unsubscribe from this group and stop receiving emails from it, send an email to tortoisesvn...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/tortoisesvn/fa53a1f8-c6ce-4bd6-bb0f-9f6e3d3e5acan%40googlegroups.com.
I just took a closer look at what is displayed from the web browser and the repo browser. The file in question is actually a '\'. It displays as a '/' when trying to check out from the command line.
After backing up the repository I would examine it with low level tools and once I found the slash I would change it to an X or a Y using a hexeditor such as Hxd. Might not work and there might be too many slashes to narrow it down but that would probably be my first angle of attack. Obviously Daniel's solution is much safer.