several strange behaviors on my opigno site

Hello, Recently i installed Opigno 2.3 on my site. Lately I discovered that some functions don't work as they should. For example: I can't edit in the learning path manager anymore; the page simply won't load on clicking the button for learning path manager(number2). Instead it goes to the add activities to modules page (number4). SOLVED This "problem" occurs when there are Modules without activities in your learning path, so doing this properly returns the editing of the learning path itself. It is possible to add a new activity from the modules page, but after clicking on the Add activity button, the filled out page doesn't have a Save option only Next. Clicking on Next doesn't save the activity though.... The only way i can add activities is going to the opigno module - list activities page... Is it possible to change the date format in the kalender now it is mm/dd/yyy, (i need dd/mm/yyyy) but supplying a new date format and selecting it in the calender event settings doesn't work... Anybody experiencing the same problems? or know the solution? Thnx in advance, viragom