Failed to create WSP in "Save site as a template"

Hello,

for a bunch of webparts I need to provide a custom web-template and include it to my WSP.
I recently figured out that I cannot create a template from SharePoint Server 2010 due to lacking features in Office 365.
My second attempt was to create a web-template from SharePoint Online for SharePoint Online.
I was able to create a website, but when I try to save it as a template I get the error:

"Error exporting the list named "Master Page Gallery" at the URL: _catalogs/masterpage".

Dows anybody have any idea? Thank you very much

koenig1985