Whenever I try viewing any project that has video blocks in it, it asks if I want to use the video but no longer works.

I have a webcam, obviously and this used to work.

I am using a Windows 7 computer with Google Chrome. It does not work with any browser though.

Those projects probably don't have a turn video on at the beginning of their scripts. Ask the creator of those projects to add it when green flag pressed.

No, they do. One of my own projects used to work fine with video, but it no longer does. I'm 100% sure there's a turn video on block there.

The bug was introduced in the latest update, hopefully it will get fixed soon.

No, it wasn't the last update. This has been going on for me for about 2-3 months and I reported it a while ago to Lightnin but I can't find where I did.