There is no specific error message for this problem, however file names with many special characters can cause errors of various types. The following characters are not allowed in file names:

#&;`|*?~<>^()[]{}$\, \x0A \xFF

Spaces are allowed in file names.

The Subversion server will treat files in a case sensitive way. In other words, readme.txt is not the same file as README.txt. Some operating systems (eg. Windows) do not treat file paths as case sensitive.