Trouble splitting a surface

Hi there, thanks in advance.
I am trying to split a surface and I have got part of it to split and part of it won’t split. I tried rebuilding the surface but that doesn’t seem to work either. Any help is much appreciated.
Thank you. Google drive link to the file

Which command are you using, which surface is to be split, and what is the splitting tool?

Hi David,
Yes that information is important!
The layers that have the exploded extrusions are the ones I am trying to split with the topo layer using split.
Thanks David!

Hello - just exporting those object, shrinking the topo, makes for a file of 43 MB rather than 750MB for every one to download.
From what I can see the ‘topo’ is not close to the extrusions in places where the split has failed.


The tolerance in the file is .5 units - that is not a good way to work- try .01 iunits


Hi @pascal,
Thank you for the tip about the tolerances, and shrinking the topo.
I appreciate it.
I did see that spot after I uploaded the piece, where there is a missing chunk, but in the other spots I don’t see any issues like that.
Do you think it could have to do with the tolerances?
Thank you,