hi, sorry for my english i'm french i made an interpolation and there is a flash effect starting during this interpolation but i have a little interruption so it's not moving smoothly
The choke that you see is caused by the pattern but it's not a bug. FESClouds has some intense processes that really "kills" the processor, it needs a half of second to initialize. You could use a smaller picture, which will "eat" less resources from your computer.