I seem to have the same problem and none of the fixes works for me (upload fails, “try again later”). My site is hosted by german hoster strato and their support have not heard of the problem. GD seems to be installed on their systems and memory is sufficient (128MB). Do the suggested fixes work at once or do I have to do something? I did not have any issues with 4.5.1, problem started with the auto update to 4.5.2.
