Fatal Error – Design -> Menue

Hi,

i get an Fatal Error: Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0
if i click Menue under Design.

Cachify worked some weeks without problems.

The rights in the cachify-folder are set to 777
and the sites are cachified without problems
http://playground.ebiene.de/cachify-wordpress-cache/ doesn´t solve the problem

Regards

PS Hoster is Domainfactory

https://ww.wp.xz.cn/plugins/cachify/