Error writing AAF

We are aware that in Catalina and Big Sur the additional security seems able to cause problems, there is also a possibility that some of the third party readers which we use to read files are unable to open them in these OS versions. You could try converting the audio to m4a and use the converted files in the project, this has been successful in some cases. We are investigating.

I'm on Big Sur 11.1 on MacBook Pro 15-inch 2016

Errors and issues as below depending on whether I stop fo rerrors or allow warnings, even though location has been added. Can't export useable AAF. What should I do?

Is this a known Big Sur issue as I hadn't had problems on Catalina.

Thanks,