I crafted a paint kit and right clicked on a block to select it, however I ended up getting kicked from my server, saying the connection had been lost. I tried relogging but I still got the same message. Even restarting the server didn't fix the issue.
Hopefully this can be fixed.

Are you using forge or fabric?
What other mods do you have installed?
Can you check your minecraft log, and the server's log?

I'm using the latest fabric version of the mod.
I'll try and send a log when I can since I ended up removing the paint kit from my inventory using an NBT editor.

We found a similar issue to this on my server, whenever we use the paint kit to select a block with weird blockstates (in our case, mushroom blocks) and then painting the inventory cables with them. For now we have disabled the paint kit.