I am getting “Bad Request” errors when committing to my repository
tl;dr
Your firewall is likely blocking WebDAV requests — ask your network administrator to allow them.
This happens when you are behind a firewall which does not allow WebDAV requests. Committing to a Subversion repository involves several new HTTP commands which some firewalls and proxies do not allow.
If you are on a company network, please ask your network administrator to allow WebDAV commands.