Blocked Plugin (not Flash) PT SE 8.0.3 - Halp!

[Tenterhook]

Tried all the tips on the forum so far. No luck, going into the studio this weekend to record my band's first full-length and need access to my PT SE (I do all my songwriting there) to mix pre-production demos.

I re-installed Flash.
I re-installed ProTools SE 8.0.3
Performed all the upgrades (1,2, 3)
I restarted (many times).
Backed up necessary files to an external drive.

I have Mac OSX 10.10.5 (didn't upgrade to ElCap)

Everytime I launch PT SE, it starts loading all the plugins, but then stops and I get the Blocked Plugin white screen and I have to force quit.

So frustrated... Please help if you can!

TIA!!