Invalid Header Error after compiled

I just compiled my first file in a long time, using the most recent version of XLS Padlock.

The first time I tried to compile it stayed on 14% for about 15 minutes, so I figured it was hung up. I closed XLS Padlock with Task Manager. I shut down Excel and re-opened it. When I re-opened the spreadsheet to try compiling again the XLS Padlock tab was missing.

I tried re-booting the machine, but it did not come back. It still showed up in Add-ins, but not in the Ribbon. I uninstalled and reinstalled and it came back,

I tried to compile the spreadsheet again. After the file compiled (quickly this time), I clicked to Test Application and received the following error.

I am using Windows 10, Microsoft 365 (not the web version).



When I click “OK” it just blinks and does not go away. I closed Excel and it still did not go away. I closed the XLS Padlock box and it still did not go away.

I tried to open the compiled spreadsheet and it would not open. There was no error message, just didn’t do anything. The error box above is still on my screen too.

Doe anyone know what this error message means?
Any help is appreciated.

Try to clear the storage folder and verify that your antivirus (if any) is not interfering. A corrupted save file means that something tampered the save files. XLS Padlock does perform several checks when you load a save file (XLSC file).