most likely a file in CMS library with id 236.
Is file with this id currently in your CMS (or was it deleted?) and assigned to your layout?
So it’s the same error as here Method: schedule manager: message invalid dependent for layout - layout12falsefalse (timestamp stuff) dependent = 254.mp
Although it seems odd in your case.
Could you try (on z64 since I know it should work) switching to public storage?
In Xibo app -> settings -> tick "Use Public Storage?“
and select first option under 'Storage Options”
It will force the device to download layout’s content again.