Make sure AE is up to date. If that doesn't fix the problem complete details of your OS, system and workflow including the type of footage you are trying to use may be required to find a solution.
Thanks for getting back to me. I'm using After Effects CC 2015 188.8.131.52
iMac Retina 5k, 27 Late 2015
Processor-4GHz Intel Core i7
8GB 1867MHz DDR3
AMD Radeon R9 M395X 4GB
I've tried various types of footage Rick and get the same error message.
Any ideas would be greatly appreciated.