Header menu disappeared after theme update on windows machines

Hello all together and thank you very much for your time. I will told you my request. After update the Sydney theme to 1.44, the header menu on windows machines disappeared. It sounds weird. On my Linux system working with Firefox ESR 52.5 , the website perfect but on windows machines (Desktop View), the header menu disappeared after 4or 5 seconds and do not come back. Everytime, i reload the startpage, i can see another time for 5 seconds the menu and than it disappeard. I tested it with win7 on iE, Google Chrome and Firefox with the same result. My website: http://arcoval.eu
Thank you very much for your help.

I have found the solution. Sorry. In my child-theme Editor CSS i had set the occupacy of header h1 tag. But it really does not have any effect in this case. Befor the update of SYDNEY Theme it has worked fine and on Debian Browsers without any problems. OK. My foult. Thanks a lot.

Hi,

Great! I’m glad it’s resolved! If you need help with anything else, please open a new topic.

Have a nice day!

Kind Regards,
Csaba