Sorry for the issue. Can you switch between your proxies and full-resolution media in the Timeline? If you can, please go to the Project Panel, select all source files, right-click, and go to Proxy > Detach Proxies. Reconnect the proxies again using the same steps and let us know if that helps.
Thanks,
Ishan
Please tag me (@) in your replies so that it notifies me and helps me respond promptly.
p.s. i don't think the adobe website, and forums in particular, are easy to navigate, so don't spend a lot of time searching that forum list. do your best and we'll move the post (like this one has already been moved) if it helps you get responses.