Hi. I’m trying to make an upgrade from suitecrm 7.4.X to 7.6.X. First I upgraded from 7.3 to 7.4 and the wizard worked properly. But when I try to upload the 7.6 version, occurs a bug and I just got redirect to the index page. Already tried to use the wizard patch, but it didn’t help.
Not sure if this could be the same problem for you but I have had issues in the past when I have run multiple upgrades and there’s a large number of files sitting in the uploads/upgrades folders as a result. Cleaning out the older versions (from within the upgrade wizard screen) was the answer for me.
I second what wondertrout said (clearing cache/upgrades/temp between each upgrade attempt) and don’t forget to check both your logs. If you have an error, it helps to know what it is!