UserForm crashes excel if workbook is shared

Hi All

attached is my userform spreadsheet

If I put this on a network folder, (which I have access to), then share the workbook, when I open it, excel crashes?

If I dont share it, excel doesn't crash and the userform opens fine

Only crashes when saved(shared) when I attempt to open the userform?

I cant for the life of me figure out why? any ideas?

Many thanks