Error uploading Rise module

Hello,

I have recently exported a new Rise module (web), but when trying to upload it to our platform the course does not upload and instead returns a blank page and the below error message. 

When comparing our older courses to the newly exported course, some of the javascript and CSS are different sizes, with differing versions. 

We have tried updating all the code to the newest version but then the old courses break, whereas if we use the old version, the new course doesn't load. We have also tried re-exporting one of the older versions to upload, but it throws the same error as below. 

Could you please advise what would be the best solution in this case scenario?

Many thanks,