Missing <tractor> INVALID displayed during transitions

What is your operating system?
Win 7 64-Bit

What is your Shotcut version (see Help > About Shotcut)? Is it 32-bit?
Just updated to the latest 21.05.01

Can you repeat the problem? If so, what are the steps?
Was using a 20. version originally which had the error of not being able to find a file when opening a project that had recently been ‘repaired’ (was just relocating files which had been renamed).
Playing the project thereafter made some transitions between clips result in a huge INVALID appearing in the preview.
Updated to the latest version in an attempt to fix it, and though the error no longer shows the transitions still result in an INVALID showing.

I saw one post say to just remove all the transitions but there’s hundreds and I’d really rather not have to redo all that again, is there any other fix for this?

Thank you.