Upload package hanging

Since updating to the latest version, I am unable to upload packages (both front and back end of course creator). I select the .zip file I want to upload but it will not upload. There is no error message,  the file simply 'hangs'. I have tried using both new .zip files and .zip files which I have uploaded successfully previously, and neither work. I have another website with an older version of WPLMS and tried uploading a package on there and it worked fine. I updated the version of WPLMS to the latest and was still able to upload packages. I then loaded an older version of WPLMS (including shortcode plugin) onto the original website I was having problems with but was still unable to upload the package. I have attempted turning off all plugins but have still had no success. I am also having this issue on another website of mine, also running the latest version of WPLMS. I have recently moved all of the three websites from a shared server to a VPS (using GoDaddy) and it seems to be since then I have had this problem. However I am confused why I am still able to upload on one of the sites? Any help would be appreciated as I we are trying to upload new courses without success! Thanks in advance