Defender Update and White Screen of Death

After updating Defender this morning I got the white screen of death.

White front end and back end. I had updated defender and disabled some caching plugins. So I wasn't entirely sure which caused it.

I disabled all the plugins via DB, and then re-enabled them one by one. After reenabling defender I got the white screen of death again. I renamed it's folder via ftp and site/admin is back.

Cheers
Jeff