I haven't tried this huge step. I recommend to do it in two steps:
1. Upgrade 5.3.3 -> 5.4.16 (or higher)
2. Upgrade 5.4.16 -> 6.3 (or higher)
But before all upgrade: Make a full backup of Database, ./data, public/data and pulic/Customizing
Ciao, Joo
1. Upgrade 5.3.3 -> 5.4.16 (or higher)
2. Upgrade 5.4.16 -> 6.3 (or higher)
But before all upgrade: Make a full backup of Database, ./data, public/data and pulic/Customizing
Ciao, Joo