Undo not working on 2.1.25?

[Speedster]

It appears that "Undo" (Ctrl + Z) does not work on 2.1.25.  I use this often to back out of a material selection. 
Bill G

[guest84672]

Works just fine for me ... ?

[Speedster]

I just tested a new, fresh, bip.

1)  On first import, all is OK.  Undo, etc. works fine.
2)  Re-import same model, not merged, with "Retain Materials" checked, "Individual Parts" not checked.  All OK.
3)  Ditto, but with Retain and Individual both checked.  Ctrl+Z not working, and materials will apply only to individual faces (surfaces) instead of the entire "part" as with 1 and 2 above.

So, now I re-import as a "raw" model only, and all is good to go.  This issue does not seem to apply when you import two or more of the same model, merging them as a group.

Bill G