Informix Error -3754: You have exceed the pseudo machine stack space.

Reasons / Common Causes

-3754 fires at runtime when the form's compiled logic exceeds the pseudo-machine's stack space — per the official guidance, this typically comes from deeply nested loops/IF statements or very complicated LET expressions.

1. Deeply nested loops or IF statements, per the official guidance — the first named cause.
2. Very complicated expressions in LET statements, per the official guidance — the second named cause.

Solutions / Resolution

1. Reduce the complexity of the form, per the official guidance.
2. Reduce the level of nesting of loops and IF statements, per the official guidance.
3. Break very complicated LET expressions into simpler ones, per the official guidance.

Examples

Breaking up a complicated LET expression

INSTRUCTIONS
  AFTER QUERY OF orders
    LET step1 = (a+b)*(c-d);
    LET step2 = step1/(e+f);
    LET total = step2*(g-h);
  END
END

Diagnostic Checks

1. Check the form's INSTRUCTIONS section for deeply nested loops/IF statements or complicated LET expressions, and simplify them.

Related Errors / Related Topics

• -2943 — "You have exceeded the pseudo machine capacity." A related pseudo-machine limit, about an overly complex expression at compile time rather than stack space at runtime.
• -2988 — "FORMBUILD has run out of memory." A related compiler-capacity limit, about overall memory exhaustion rather than stack space specifically.

The form's logic exceeded the pseudo-machine's stack space at runtime — simplify nested loops/IF statements and break up complicated LET expressions.