Premiere Pro Warp Stabilizer requires clip dimensions to match...

Been working to learn Premiere Pro (PP). Have done about 10 or 12 videos with no problems. About half of them have been shot with my Canon 6d and I used Warp Stabilizer on all of them to stabilize the video.

Working on my latest and, all of a sudden, I'm getting this message. I've looked it up on the Internet and it says this comes up with clip dimensions don't match. I don't know why this is coming up since it's all from the 6d with no settings having been changed. I just did another video in PP that I did before this one (I do real estate stuff) and it processed just fine. I honestly haven't changed anything.

Anyone got any ideas on why this is happening? I'm trying to get around it by nesting the videos but not sure how well this is going to work. Don't want it to happen again either.

Thanks.

Oh, it's also giving me this error on ALL of the videos imported into this project. Again, I did nothing different than I've been doing. This just started.

This used to anger me to no end and I'm not sure if what I'm doing is exactly right but it seems to work for me:

First right click the footage then "scale to frame size"
Right click again then select "nest"

Now you'll be able to stabilize