When I entered some multi-byte (Japanese) characters into "Admin"-"Configuration"-"Project Name" and clicked "Home" link, Fossil indicated wiki name error. (But the garble did not happen.)

"表", "予", "申", "能", "十" and "ソ" are well-known characters in Japan as trouble maker. Because '\' (0x5c) is included as a part of each multi-byte character when these characters are encoded as shift-JIS (cp932). Shift JIS (cp932) is code page of MS-Windows Japanese version.