I'm unable to craft the normal lantern in 1.12.2, after I updated the mod.

Please use the appropriate template. What version of Additional Lanterns are you using?

I wasn't aware of a template, my apologies. I'm using version 1.0.4

Seems I forgot to add the regular lantern recipe in 1.12 after converting everything to data generators 🤦‍♂️
It is fixed now in version 1.0.4a for Minecraft 1.12.

Thank you for reporting the issue!