For the record, in case anyone is having a similar problem, I managed to work around it (although it took some effort). I downloaded
AutoHotKey and wrote a simple script to add the files to the library one at a time. The script basically looked like this:
#space::
loopvar = 0
Loop 7185
{
Send, {ALTDOWN}f{ALTUP}a
WinWait, Add To Library,
IfWinNotActive, Add To Library, , WinActivate, Add To Library,
WinWaitActive, Add To Library,
Send, {SHIFTDOWN}{TAB}{SHIFTUP}
Loop %LoopVar%
{
Send, {DOWN}
}
Send, {ENTER}
loopvar := loopvar + 1
}
It loops through all 7185 files in the directory and adds them one by one. Unfortunately it gets slower as time goes on and requires much babysitting. It took me about five days to get everything added properly, but if I was paying more attention and modifying the script every few hours or so I could have probably done it in two days or less.
What a pain!