[Neos] Could not read page metadata from response. Please open the location error message

[Dominic Garms]

Hello,

What exactly does this error message mean:

Could not read page metadata from response. Please open the location 
(...) outside the Neos backend.

I have this error currently on all subpages of my Neos backend. If I 
open the locations outside of Neos there is no additional error, but as 
I can't edit the content the pages remain empty.

There is no additional error inside of the server log, its very hard to 
find out which *.yaml, *.ts2 or html template is responsible for this 
error. Is there any technique I can use to tackle this issue? Is there 
some sort of reset possible to clean up all nodes with the current 
configuration?

Happy and relaxing Sunday to everybody,

Dominic