After updating to After Effects 2018 when I try open projects made in the previous version i'm bombarded with multiple errors such as "Could not open the file...", "Unable to open the file.... If the file is opened in another application...". This pops up for each video asset I have in the projects.

I've tried converting these files to another format and saving to a local HDD rather then the network they were on but still get the same issue. I've also tried back-saving, deleting old preferences files, clearing cache etc.

AFX 2018 is barely usable at the moment for me and i'm struggling to get anything done as every couple of minutes I have to click through anywhere between 10-100+ windows of errors.

I'm running AFX on a high end PC which has never had any troubles.