Found multiple WBServer.dat files in use while opening a file.
If the WBServer.dat location has been set to a separate mapped drive (in BRConfig.sys, by the use of a WBServerconfig statement), and that drive got rebooted,than workstations that were in BR! will continue to function properly, but other sessions that newly launch will receive 4175 errors.
Remedy:
Delete all the WBServer.dat files. (del \wbserver.dat /s)
Exit BR! on all workstations. Once every workstation has completely exited BR!, they may all re-enter.