When I try to export the source of a course (AT 0.10.0/2.4.0), the export stops and I get this error in the browser console (Chrome):

Does anyone have a similar experience?

It is only the one course that has the problem (it is also the largest).

I just discovered, that the export zip-file is generated on the server, and I can download it from there.
So it seems to be the download part that fails.