C2D

Explanation
A program requested an overlay.  In answer to the
request, the overlay supervisor was using program fetch to load a
program segment from the library.  Fetch could not get enough storage
for the module or control blocks.
Note: Overlay programs run only
in 24-bit addressing mode, not in 31-bit addressing mode.

System action
The system abnormally ends the program that requested
the overlay.  The system writes an ABEND dump, if a dump DD statement
is provided.

Programmer response
Determine why no storage was available.
 Correct the errors; then assemble, link edit, and run the program
again.

Source
Overlay supervisor