https://github.com/nextcloud/richdocuments/issues
If you are looking for any warranty or liability on the part of the developers towards you in case the software causes any problems or defects, I am sorry to disappoint you, because there is none.
Are you new here? 
I don’t think so, and I think you know how it works by now. You can open an issue yourself on GitHub at any time.
But please update Nextcloud and all the apps to the latest version first, I think by doing so you will have a good chance that the issue will resolve itself.