Fatal Error when calling macro via Alt+F8

Dear all,

I am new to this forum, so please forgive me, in case I wasn't able to find an archived post that may have already covered this.

I am fairly new to the world of VBA and have recently programmed two procedures which add rows, format them in a specific way and enter the current date, copy parts of the row from above, etc. I use an Excel based timesheet during my work so I thought I'd take this as a starting point to dive into this exciting topic of VBA in Excel.

Anyhow, for a reason I don't get, Excel now sometimes crashes, when I call (any) macro in this Excel (time-)sheet via Alt+F8 and says there was a fatal 'automation error' (It's in German, so I don't know the exact wording of the English error description, see screenshot attached)... I really have no idea where to start and searching the net didn't help me either.

The error cannot be replicated every time. Sometimes it works fine, sometimes it crashes (in particular right after opening the workbook). Note that executing the Macro from the VBA editor works at all times with no errors.

Thanks a million for your support in advance and best regards

bubi1080

One thing I did notice just now is that the symbol for alt+f8 in my quick access bar changes. Right after opening any workbook it looks like this
symbol1.png

To change after a few seconds to this
symbol2.png

Not sure if this makes any sense...

Thanks a lot!!