Strange Z co-ordinate on display at end of print

When print is finished, i get nan as the co-ordinate of Z axis.
I then always have to manually reset the Z axis.

any ideas?

Imported from wikidot

Can you show us your config and an example ( preferably very short ) gcode file that causes the issue ?
Also, does homing solve the issue ?

yes re-home it does fix

cant test again as i sold my azteeg board.

if i have some time i will dig up a old mks sbase board.