@succli - asking you to change back to the default theme is not offering a solution. Rather it's a common WP problem solving technique. You only need to switch temporarily to see if your theme is causing a problem.
If the problem remains you know your theme is OK. If the problem is fixed you can hopefully start solving the problem within your theme.
By the way I'm not suggesting you switch to the default theme, I'm just explaining why you might be asked to do that when you ask questions in the WP forums.