For the life of me, I couldn't figure out why I was unable to checkout from my Subversion repository while I was at work. It worked while I was at home (where my Subversion server is) just a few days ago, and I can view the repository using Subversion's built-in web page functionality, but if I tried to access the repository from the command-line client or TortoiseSVN, I would get an error message.
C:>svn co http://MyServer/Path/To/Proj/ MyProj
svn: REPORT request failed on '/Proj/!svn/vcc/default'
svn: REPORT of '/Proj/!svn/vcc/default': 400 Bad Request (http://MyServer)
Yeah, that's not cryptic. Fortunately, the solution is simple. Sander Striker explained in a thread REPORT request failed ... 400 Bad Request that if you're behind a proxy at work, and the proxy isn't configured to support the necessary Subversion calls REPORT, your request will fail.
Like he says in his message, you could request that the proxy be configured to allow the necessary requests, but you could just as well configure your server to work on a different port. Now, I like the fact that my Subversion calls can work on port 80, and I don't want to change that. So, I configured Apache to have my Subversion sites work on an additional port.
In the following example, let's use port 81 as the additional port. So my example URL http://MyServer/Path/To/Proj/ would become http://MyServer:81/Path/To/Proj/.
At the following spots in your httpd.conf file, make the one-time additions as marked in bold italics:
Listen 80
Listen 81
And...
NameVirtualHost *:80
NameVirtualHost *:81
And for every virtual host entry you have for a Subversion site (I host a couple different Subversion sites), add *:81 in the VirtualHost header:
< VirtualHost *:80 *:81 >
After restarting Apache, you will now be able to continue to use the URLs you normally use, but anytime you need to checkout from the repository while at work behind a proxy, you can use port 81 to do so successfully.