Vendor / Product Owner Keeps Loading

Hi, I hope someone can point me in the right direction. I never had this issue before, but suddenly I can't change the product owner of a product anymore. It just keeps loading forever. Please see attachment.

Would anyone know what causes this?

Thanks!

vendor keeps loading.jpg

Check developer console of your browser for errors

I found out it's caused by the Cloudflare Security - WAF (Web Application Firewall)

Cloudflare Specials, Managed rules

100135A
XSS - JavaScript Events
Disabling this fixes it.

Thank you for letting us know it

My website keeps looping now as well even after deleting the cache folder and I can't start a new topic on this forum.

I had the same issue after updating to 4.14.3 today. I had to disable modsecurity to make it work. But is it possible to debug this issue without disabling the modsecurity?