Hello John,

It should be fine upgrading from 1.2.15 to 1.2.20 However, there has been massive changes since 1.2.15 to the database structure. It's best that if you could test this on a test site first before directly upgrading it on a live site.

I'll do that. If it does not work, what upgrade process would you suggest?

Hello John Whelan,

Sorry for late reply to this,
May i know which stage your stuck in installation.?
Can i have your test site login credential of Joomla backend and FTP access so we can see what is the issues causing this installation is not working update from 1.2.15? Please advise.

Not stuck. Just getting ready to do the upgrade from 1.2.15 to 1.2.20. Sometimes these upgrades cause problems, so I wanted to check in advance what to expect.

Hello John Whelan,

As Mark suggested you can do a testing from your test site, because we hard to make sure that because it depend on what issues after you update from 1.2.15 to 1.2.20, then we will investigate on this and provide a better way solution with this. Hope this help.