Hello, new to this forum but I have read around. I use VideoPad for YouTube videos, previously I edited on an old HP laptop with 3gb ram and an AMD processor running 1.3ghz. On that computer I couldn't ever see a preview after increasing the speed of clips (pretty much the only effect I use). I had to guess at the final outcome and export my videos on faith. I just bought a brand new desktop with 16gb ram, intel hd530 graphics card, and i7 3.4ghz processor. When I opened a project I had started on the laptop on the new desktop it previewed and ran great! Then I changed the length (not speed, I split the clip and deleted the latter half) of one clip and now that one clip will not play in preview. It perpetually claims to be building a preview. I cleared the cache, saved. closed and reopened the project, cleared the cache again, the problem persists. I thought 16 gigs of ram on a 6th gen processor would be plenty. It will currently play the project fine right up until that one clip, will "build preview" for the duration of that clip, about 20 seconds, then continue to play well. Any advice? Am I just being impatient? I'm afraid to do any more editing until I know why this happens. Thanks very much Kai Quick update: I added new clips onto the end with speed changes and they preview fine, that other clip still won't play. PS: search KaiCrafted on YT if you're interested in woodworking, metalworking, or sculpture.