Just run in to the same issue. Found that this is because CA tries to keep forms backwards compatible, and the issue may appear after migration to R12
// For R12, if it's using role, we use the menubar
// defined in the main form for the tab page.
<PDM_IF "${args.KEEP.use_role}" == "" || "$prop.menubar" != "">
// For supporting pre-R12 HTMPL files, we still
// include a hard-coded menubar file.
<pdm_include file=menubar_${prop.menubar}.htmpl>
So i changed
<PDM_INCLUDE FILE=std_body.htmpl filename="Incident" key="$args.ref_num" menubar=sd > to
<PDM_INCLUDE FILE=std_body.htmpl filename="Incident" key="$args.ref_num">
and issue was solved