I'm scared to upgrade my site to the latest XF version. Should I be?

[Hensmon]

I just saw that my license ran out in 2021. I would like to renew and upgrade my forum to the latest version, but have big concerns. I have done so much customization that I worry that loads of bugs will appear if I go for an upgrade. Not just add-ons, but custom front end stuff too. Is this concern legitimate?

Also I have no idea what version I am currently running. I cant seem to find that info in my admin panel.
I'm scared to upgrade my site to the latest XF version. Should I be?

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