U4093: Language Environment initialization error

What it means

This page covers user abend 4093 as issued by z/OS Language Environment (LE), the runtime for COBOL, PL/I and C. Other products can issue a user abend with the same number for their own reasons. If the reason code and messages come from LE, this is the code you have.

Before the first statement of a program runs, LE builds its runtime. It gets the first stack and heap storage, loads its own modules, sets up condition handling, and calls an event handler for each language in use. In a z/OS UNIX environment it also sets up condition handling with z/OS UNIX. If any of these steps fails, LE ends the step with U4093. In one of IBM's documented CICS cases, LE also wrote message CEE1000S with abend code 4093 and the reason code.

The reason code tells you which step failed. IBM's support pages describe two of them. Reason code X'34' means a language event handler returned an error to LE during startup and LE ended at once. X'90' means LE couldn't set up condition handling for z/OS UNIX. Look up any other value under abend 4093 in the LE runtime messages manual for your release.

Common causes

• Not enough storage. The REGION on the job or step is too small for LE to get its initial stack and heap. It is one of the causes reported most often for U4093 in batch.
• A z/OS UNIX resource limit, with reason code X'90'. IBM documents a case where CICS failed at startup because the user ID had reached its MAXPROCUSER limit for processes.
• A language event handler failing at startup, with reason code X'34'. IBM documents a case in CICS where a debugging tool's handler failed after the tool was stopped with its FORCE option.
• A product or tool that inserts itself into LE startup, such as a debugger or a monitor, running at a level that doesn't match the compiler or LE release.

How to find the problem

1. Note the reason code. It is in IEF450I, the symptom dump (USER COMPLETION CODE=4093 REASON CODE=...) and, in some CICS cases, in a CEE1000S message.
2. Look for other CEE messages in the job log or the region's output. For reason X'90', IBM's example showed a CEE5101C message naming the z/OS UNIX service that failed and its reason code.
3. Check the REGION for the step and the job. A step that ran before with the same program but fails now often has a smaller REGION, or a bigger program, than last time.
4. Check what else hooks into the step, such as a debugger, a monitor or an exit, and whether it changed recently.

How to fix it

• Raise the REGION on the step or job. Increase it in steps, or use REGION=0M if your site allows it, and rerun.
• For reason X'90', raise the process limit. That is MAXPROCUSER in the BPXPRMxx parmlib member, or PROCUSERMAX in the user ID's OMVS segment.
• For reason X'34', find which tool's handler failed and follow its vendor's fix. In IBM's documented case, stopping the tool without FORCE ended the abends.
• For any other reason code, search IBM's support site for abend 4093 with that code. Many entries name a PTF or a setting.
• Storage and parmlib fixes belong to whoever owns the JCL or the system. Tool problems go to the team that runs the tool.

What it looks like

IEA995I SYMPTOM DUMP OUTPUT
  USER COMPLETION CODE=4093 REASON CODE=00000090
IEF450I INVLOAD1 STEP010 - ABEND=S000 U4093 REASON=00000090

Last reviewed 2026-10-18 by the WND Software team. Written in our own words. For the full reference, check the documentation of the product that issued the abend, for your release.