More problems with editing word abbreviations

[Ronald I. Greenberg <RIG at MIT-MC>]

In ZWEI in Release 5.1, Experimental MIT 1.4, FEP 18, on TELLURIDE (3600):

     I have now found that even when in the correct mode, hitting a
carriage return while editing word abbreviations yields the message
PROCESS ZMACS-WINDOW GOT AN ERROR and puts SELECTED instead of Tyi in
the information line at the bottom of the screen.