UBB.threads PHP Forum Software Community Forums UBB.classic UBB.classic 6 Support rebuild index option goes to blank screen

I am unable to rebuild my search index and update my member post histories. Choosing both of these options sends me to a blank screen. Although sometimes, it begins to rebuild my search index then it stops and generates a blank screen. When this occurs I attempt to go back (browser) and resume the process. That only works once or twice, but I can't complete the indexing process.

Any suggestions.

verion 6.2.1
Netscape Enterprise Server