Panasonic KX-T336 System Reference Manual page 1124

Error Message No.
141 Attempting to remove an extension or trunk port
which is registered in Power Failure Transfer
(PFT) assignment.
150 Impossible to change the Numbering Plan to
"Fixed," because there exist DN's which should
be blank in the "Fixed" mode in the Hundred
Block.
160 Impossible to change ICM/Paging group, for the
pickup group belonging to the ICM/Paging
group contains extensions.
Probable Cause
9-M-6
(70695)
Countermeasure
Cancel the PFT assignment of the
corresponding card, and then delete the port.
Clear DN's which should be blank.
Change after deleting all the extensions in the
pickup group.