Stacc 1.16.1 6
Minecraft 1.15.2

When you attempt to rename any item (without repairing or enchanting it) at any stack size in any anvil (in Survival or Creative mode), the operation is rejected. The only way to rename an item is to repair or enchant it. In Stacc 1.16.1 5, renaming was still possible for any item. Most likely caused by the XP cost fix in #5.

I can confirm that this issue is present. It doesn't matter what Stack size you have configured you simply can't rename items unless you repair or enchant them (like James103 mentioned). The current Github repo isn't up to date so checking what the issue is is impossible.

hm

yep fixed

was this fixed, I think it is, imagine testing your own mod hahayes

I'm not sure, I had to remove this mod eventually because it conflicted with some mods (can't remember which ones).