If you cannot open a course or single course elements it may be that the course author has not given you the relevant rights or the course is being updated at that very moment.
Given the case that you have just found an interesting course and want to get to the course view. If you are notified that you do not have enough rights to launch that course this means that the course is restricted to a certain group or to a certain period of time. A course could also have been password protected in an earlier OpenOLAT version, which allows authors to restrict course access independently of groups or time.
Perhaps you have been able to launch a course but later on you get an error message telling you that its authorization has been changed. This means that the course author has restricted the access in the meantime or closed that course.
If the course author changes the password at a later date, all users must re-enter the password.
In all cases please contact the course author to grant you access.
Perhaps not the entire content of a course is visible or you have no access to certain course elements. This means that the course author grants only particular groups access/visibility to that element or only for a certain period of time.
The course element "Structure" may also be password protected, including all sub-elements. Access to individual elements can thus be restricted independently of groups or time.
In both cases please contact the course author to explain why you do not have enough rights.
When working on a course and getting the message that the course has been modified, the course author has just updated that course in the meantime. Click on the button "Close course and restart" to get to the updated course version.