Is there a tool available to find out which add-ons, I have already downloaded before Sim update 5,are not compatible?
Yes, it's called loading into the sim one at a time until your sim crashes.
A short cut that may or may not work is to leave out all the aircraft and liveries that aren't marked as OK, and try loading all the sceneries and all the utilities. If the sim doesn't crash, then you have a fairly safe set of non-flying addons.
Then try that with your aircraft and liveries that are not marked as OK, and again, if the sim doesn't crash - you're OK. If it does crash, just load the aircraft and their liveries one at a time until you have eliminated all of the "crashers"
Oh, and any of your addons that have been updated since July 29th should be fine.
John I like your first line. Straight to the point with no frills attached!