This wandisco forum post will lead you in the right direction. Assuming you have access to the repo server, you need to disable compression with mod_deflate.
To resolve this error when attempting to export a large (> 4GB) repository on Ubuntu 12.04 LTS, do the following:
On the server hosting the repo:
mv /etc/apache2/mods-enabled/deflate.load ~/backup_deflate.load
mv /etc/apache2/mods-enabled/deflate.conf ~/backup_deflate.conf
mv /usr/lib/apache2/modules/mod_deflate.so ~/backup_mod_deflate.so
sudo service apache2 restart
As described in other posts, changing the client is also a workable solution. With access to the repo server, this approach was faster to implement and required no changes by the users.