Informix Error -2830: A left square bracket has been found on this line, with no right square bracket to match it.

Reasons / Common Causes

-2830 fires when a [ in the SCREEN section has no matching ] on the same line — per the official guidance, screen fields can't span multiple lines and must be fully delimited within one line.

1. A missing closing ], per the official guidance — the direct, only cause.
2. An attempt to span a field across multiple lines, per the official guidance's own framing — not supported; use multiple complete fields sharing the same tag instead for a multiline field.

Solutions / Resolution

1. Review the SCREEN section to ensure all field brackets are properly matched, per the official guidance.
2. For a genuinely multiline field, mark multiple complete fields with the same field tag, per the official guidance, rather than trying to span one bracket pair across lines.

Examples

An unmatched left bracket

SCREEN
{
[f000
[f001]
}
-- -2830: f000's [ has no matching ] on the same line

Corrected

SCREEN
{
[f000]
[f001]
}

Diagnostic Checks

1. Check every [ in the SCREEN section for a matching ] on the same line.

Related Errors / Related Topics

• -2820 — "The label name between brackets is incorrectly given or the label is missing." A related SCREEN-section bracket error, about an invalid label inside matched brackets rather than an unmatched bracket.

A [ has no matching ] on the same line — screen fields can't span lines; use multiple same-tagged fields for a multiline field instead.