The .xlsm extension tells you that the workbook can contain VBA; it does not tell you which protection layer is blocking access. Diagnose the layer before changing formats.
A password before any workbook content is visible is an open-password case. A workbook that opens but blocks cells or sheet structure has sheet or workbook protection. A VBA project can also be protected independently. Treat these as separate problems with separate evidence.
Recovery process
A password before any workbook content is visible is an open-password case. A workbook that opens but blocks cells or sheet structure has sheet or workbook protection. A VBA project can also be protected independently. Treat these as separate problems with separate evidence.
Microsoft identifies XLSM as a macro-enabled Open XML workbook. Excel for the web can open an XLSM, but macros do not run in the browser. Keep a desktop copy, note the Office version, and do not use a format conversion as a password workaround.
Make a byte-for-byte copy before opening, resaving, or testing. Saving a macro-enabled workbook as XLSX can discard VBA. Do not enable unknown macros just to inspect a prompt; submit only a file you own or are authorized to process.
These details help with the first profile check.
The outlook depends on the actual encryption profile.
Common situations
Make a byte-for-byte copy before opening, resaving, or testing. Saving a macro-enabled workbook as XLSX can discard VBA. Do not enable unknown macros just to inspect a prompt; submit only a file you own or are authorized to process.
Next step
Start with format detection and choose the appropriate path only after the file is identified.
Technical details on this page can be checked against the original format or vendor documentation.
