>can't imagine it's a codec issue
Imagine again... your screen print says they are bitmap files... IE a string of pictures, not "really" a video that PPro recognizes... and a 40fps frame rate is also "odd"
Does autodesk have any other output options... to create a file with a "real" video codec?
Since editing is not the same as playing, you MAY need to find a codec to install to be able to edit (NOT a codec pack !!!)
Does autodesk have a place where you can download and install "their" codec to edit the files?
The only other option Autodesk has that I know of (I'm not the drafter who rendered it), is .wmv or .avi. I've seen the .wmv files that are exported out of it, and they're artifacted pretty bad. I have had no issues with these same type of .avi renderings from inventor before.
I know the 40fps is kind of odd, but I asked him to do a higher fps than the standard 29 or 24, because I will be slowing down the animation in Premiere Pro, and the more fps would lead to a smoother video.
I have looked for Inventor .avi codecs with no luck.
Ok, I figured out a workaround. I'm going to mark your comment as the answer because it pointed out something I didn't notice.
Since you mentioned it was a string of pictures, I imported the video into Photoshop and rendered it out into an .mp4 format. There might have been a little quality loss, but at least I can work with it. Thanks for the help!
Glad I was able to help, even if not a direct answer... and that you now have a file you can use in PPro