The 12.1 updates makes random distortions/glitches and .png files, and other clips
The 12.1 update has completely messed up all Premiere saved project files and clips contained inside them, showing random distortions/glitches and .png files, and video clips, and then random placements again upon export, which are not visible when going back to the timeline for review
Please, specify your configuration.
If I understand correctly, I do not have this problem on :
Windows 10 Pro v 1709 (10.0.16299 ) uptodate 2018-04
Core i7-3930K/3.20 GHz 12MB 64Bit
ASUS NVDIA GeForce GTX 680 2Go Pilote v 391.35 03/27/2018
64Go RAM DDR3
Premiere pro v 12.1.0 (Build 186)French.