upgrade path?

I can't upgrade 5.21.2 app to 6.x. whats the way to go? First 5.21.4, then 6.01? or????
1 answers

I was advised to upgrade to 5.21.3 (when I was upgrading from 4.1.1) as this version addressed some upgrade issues. I did so and was able to upgrade to 6.4 from there. So I would try upgrading to 5.21.3 or 5.21.4, then 6.4. But first of all make a backup, so if it doesn't work you haven't lost anything!