There was a sudden language switch from English to German on my MM 11.2 for Mac (iOS 10.14) for absolutely no reason. I tried to re-install it without success. Could you please help me? I'd be so grateful.
I am intrigued by your remark: "for absolutely no reason". If you don't know the cause, repairing the symptom is not the best way to go. So please check:
Could it be that someone in your family or a friend or colleague has used your lap/desktop?
Did you install any new software that has changed the settings on your OS? Do you have a new keyboard layout?
Did you visit Germany or came close to the Austrian border?
In the Windows version of MindManager 2019 it is possible to change the language setting via File=>options=> general and there you can select your working language. I don't know if this is the same for Mac versions. And even so... you are on MM 11.2 for Mac and the latest version is MM12.x
If all fails, go to Mindjet support via the mindjet website. They will be glad to help you.