I wonder if it would play correctly if you imported the video using the media browser. Other than that, we'll need the info that Ann asked for above to get you some proper help!
This is the transcript from adobe support which fixed problem\\please do the following stepsready1.
Go to the documents folder >> Adobe >>> rename the Premier pro folder as premier pro.oldThis may take a minute as I have more than one doc folderokay, but there should be a main folderdoneokay now launch the premier propokay, please check the issue and let me knowOkay it is working now. Wow. Thank you. So simple yet so unknowableThank you again
Thanks to all who replied