LiveCycle and AEM forms Generate PDF service does not support converting an XLSM file to a PDF document.
The Generate PDF service does not support XLSM files, but it supports XLS and XLSX files. Use Microsoft Excel to convert existing XLSM file to an XLS or XLSX file. Then, use the Generate PDF service to convert XLS and XLSX files to a PDF document.
When you save an XLSM file as XLS and XLSX file, the macros associated to the XLSM file are removed.