Hi,

i get everytime 500 internal server error if i try to upload image in backend, permissions are ok. and i use K2 v2.6.8, i can't found any php error, how can i solve this problem?

Hi. A 500 error is very generic and provides no details. You need to look at the server logs to find the error. Instead of that i suggest that you set error reporting to maximum under Joomla! configuration and also enable system debugger. Finally check PHP's memory limit of your server and that it has PHP GD installed.