The map number used to be limited to 4 digits, but for the last few versions has been any 32-bit integer. Unfortunately, the space in the dialogue box is still only large enough to show 4 digits. It's not as if there is any lack of space after the 'Map number:' label.
Best wishes,
Matthew
Thank you for the report. Can anyone confirm whether this is unique to Experimental or also needs to be changed in Standard? It should in principle be straightforward to remedy.
This text is much longer in other languages, that is why.
Ahh, I see. Is there anything to be said for widening the box to the right, in that case?