Adding Effects Results In Visual Bugs

[Pattles2]

I'm a beginner Premiere Pro user who commonly adds effects to my projects, so today while trying to assemble a file from multiple clips, I tried to include transitions. When dragging an effect no issues. But after replaying the clip with the added transition, this video goes completely haywire. I've looked at the Adobe support page but couldn't find any fixes. I have tried rendering the file & effects, but this didn't solve the problem.

How do I fix this?

Running OS 10.14.6 on a MacBook Pro

[Ann Bens]

If the footage is variable framerate convert to constant framerate with Handbrake before bringing into Premiere.

[Michael Grenadier]

just to fill in somethings Ann hasn't mentioned.  variable frame rate footage usually comes from screen recordings or smartphones...

use mediainfo to determine whether your source is variable or constant frame rate
https://mediaarea.net/en/MediaInfo/Download
if it's variable use handbrake to convert to constant frame rate
https://handbrake.fr
and here's a tutorial on how to use handbrake
https://www.youtube.com/watch?time_continue=34&v=xlvxgVREX-Y

[Kevin-Monahan]

Pattles,

Apologies. Set Audio Hardware prefs Default Input > "No Input". See if that helps. Report back if it does.

Kevin