I have experienced the same when upgrading from Studio 18 to 20, where some video files suddenly wouldn't play in Studio.

What I figured out is, that the 64-bit version of Studio supports fever video formats than the 32-bit version -  Divx, H263 etc. can be troublesome, and have to be converted to H264 (AVC) to be used in the 64-bit version.

I therefore always install the 32-bit version of Studio, and haven't notice any difference in performance.