Oft übersehen Forum-Nutzer den „Gelöst"-Button oder nutzen ihn nicht, wodurch die meisten Support-Themen offen und ungelöst bleiben.
Ist es möglich, dass Administratoren und Moderatoren Themen ebenfalls als gelöst markieren können?
Yes. Staff could solve all the topics. 
Check the “category” options with solved plugin.
Exactly, it’s under “Edit > Settings > Allow topic owner and staff to mark a reply as the solution”
Thanks for the swift responses! I don’t see an ‘Edit’ menu, and searching the Settings options for “Allow topic owner and staff to mark a reply as the solution” yields no results. I have this option, which is checked:
Menu - Admin - Settings - Plugins - Enable solved plugin, allow users to select solutions for topics
There are three other options on the Plugins settings page (also when I search settings for ‘solved’). They are depicted below.
Am I missing something?
You need to enable it per category. So edit the category, then head to the settings tab there.
Got it, thanks. ‘Allow topic owner and staff to mark a reply as the solution’ was already ticked, yet still there is no option for me as an Admin to mark a topic solved. For my own topics (ones which I created, in the same category) I can see this option. But not for topics created by others.
From your collective comments it sounds like I should have that option by now?
Look under the ‘…’ icon. For some reason, it’s hidden by default for moderators and admins.
@bartv Wow that got it, thanks! All done.