Thanks for the reply. I have the project already loaded and open. All assets are in their folders. If I go to any other window and come back to VP, that is when it happens. Every time.

I work sometimes on large projects with hundreds of clips in 11 bins. I have one bin open with 116 video clips. Switch to another window and come back... spinning blue circle. Open another bin with 9 clips, go to another window, same thing. My system specs are in my sig.

With taskmanager open. I'll wait until VP CPU usage is at 0% while I am in VP. Click on any window and come back to VP, CPU usage automatically starts to slowly increase to 7.7% while the spinning blue circle goes. Once CPU usage is back to 0%, then the regular mouse pointer is back and I can start working again.

I said not about opening project, but project's medias.

When you switching from VP to another program VP closes medias (to release some resources). So when you switching back to VP it is re-opening closed medias and re-building timeline thumbnails.

If you doing this quiet often you can change the option so VP will NOT close medias when you switch from it to another program. Also, you can disable thumbnails or make them only at the beginning/end that is way faster.

Ok... I am not clear on "rebuilding project media". What specifically is that, since I see all the thumbnails on both timeline and in project bin I have open.

I have thumbnails on the timeline beginning/middle/end, 3, that's it.

I would rather this not happen so would appreciate on what I have to change to stop this.

Thanks.