Excel 365 - Template "Checkliste für Urlaub" not working

Hello,

I have Windows 10 Pro (April 2018 update) and Office 356.

Both are in German language.

I create a new excel file and select the template "Checkliste für Urlaub" (the checklist for holidays).
I can normally use it (set the check mark in the first column via a double click and remove all checkmarks with a click on the button "Löschen" (delete).

I save the file as Checkliste.xslm (Excel Worksheet containing macros) on my local HDD.

But after I open it again (double click in the file manager) the button "Löschen" is not working (see attached error message in German language) and also not the double click in the first column to delete/set the checkmark.

When I open the file I do not get any message that macros are disabled.

And I can execute macros in other Excel documents.

So I really don't know what is the problem.

Any ideas?

I already posted in the German Microsoft Cimmunity but they were not able to help me and suggested to post here:

https://answers.microsoft.com/de-de/msoffice/forum/msoffice_excel-mso_win10-mso_365hp/office-365-vorlage-checkliste-für-urlaub/00ea1780-7f8d-4cd5-ae82-bd03bd01b75c?messageId=735484ab-90a4-42df-be66-3d7ff96503b0

Regards

OLLI