There was one package which I use which changed significantly some time ago and I chose then to stick with the version which worked and needed no changes in my code. It's never a good idea to stick with old versions so I bit the bullet and have changed this site to use the newest version. It's well tested, but if you do have any issues uploading CSV or Excel files please let me know.
The payment page was broken. Last year I thought that I had moved away from the deprecated method which I was using, and I had, except in one important respect. I now use the correct card entry form so payment will work again.