Stock by Attribute v4.0 addon for v1.3.5-1.3.9

[DivaVocals]

A blank page usually results in something being written to the error logs. Have you checked them for any clues?

Cheers
RodG

Have not. When the blank screen came up, I deleted all and reinstalled.

I am curious though... looking back to my original question...Why would SBA 1.5.3 work on one site with ZC 1.5.4 and not another? Both sites identical except for the templates and, of course, name. Both running on the same host , same platform, same php level.

We can't answer that.. because we don't KNOW what went wrong.. and we don't know what went wrong because you have yet to post your error log messages so we can SEE what happened on that store.. Post the error logs that are created when you get the blank page, and we can get you a better answer your question.. (and probably help you resolve your issue) Without that information, this will just be one of life's little mysteries..