Ultimate Membership Pro - crashing wordpress site

I have the Ultimate Membership Pro plugin in, and since October, when uploading the updates, they crash my site. I am actually in the midst of moving this to another plugin, but in the meantime I need this. Any one have hints of what to do? I should have copied the error message (but I did not)

The best way to get the support is Contact your purchased plugin Author. Contact Author because plugin Author are best expert about their Item functionality. Don’t worry just contact Author and let them know your concern. Author will be very happy to assist you.