No source displayed in CICS debug session.
This is a problem I come across quite often. There are several steps a developer can do to resolve the issue before calling IBM for help:
current program loaded is not prepared for Debug Tool
This can happen if the program is not loaded from the expected library. CICS found an older / different version of the program first in the DFHRPL search path. Issue DESC LOADMOD in the debug session. Here is an example of the output:
ADDRESS LENGTH ... [More]