After I attempt to commit my code with svn commit, it returns a mistake :

svn: Commit unsuccessful (particulars follow): svn: Server sent unpredicted return value (405 Method Not Permitted) in reaction to MKACTIVITY request '/svn/!svn/act/acf5cd6f-e8d7-476e-a572-a61a5d293586'

How is this fixed?

Try switching to https appears like this can be a bug in the search engines Code system, see Google Code Bug #1916