Cannot Export XML in OJS 3.2

[marc]

What is your exact 3.x version?

Looks very similar to this issue:

• Error 500 on DOAJ Register
• DOAJ deposit action not working · Issue #5939 · pkp/pkp-lib · GitHub

That was patched in 3.2.0-4.

Anyway, upgrade to the last LTS is always a good idea.