I made a coding error in changing a contant (string) to a simple public variable and corrupted my file.
The current version of data in one spread sheet is not backed up, and I seek to recover it
All developer code Is backed up
When I attempted to open the xlsm file, the Excel announcement screen opened, and reported the correct name of the file it was opening. After a long delay, it reported that it was "Opening and repairing" the file as "Attempt#1".
After 15 minutes, no progress had been achieved.
For example, can I recover this spreadsheet data, say by converting the xlsm file to xlsx (without opening it)?