Thanks for this reply. I'm using Firefox 59.
Asking Dr. goo+++ I found this hint: https://stackoverflow.com/questions/15868345/bootstrap-doesnt-work-in-firefox?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa
So there is a gap in Firefox to IE with bootstrap.
I will try IE instead.
Great tool. As I need to reinstall Office 2010 Home and Student I was looking for a download link. Unfortunately the tab asked for the edition, done. Then there appered an empty product lang combo box....
How to preceed?
Thanks
Andnewbiw