Troubleshooting: Litematica Server Paster Not Working After Install

First: is the mod actually loaded on both sides?

The Server Paster mod requires installation on the client and the server. If only the client has it, the custom chat packet is never understood by the server, and you get vanilla-length commands with stripped NBT. Check the server's mod list, not just your own.

Second: the two required Litematica settings

Open Litematica's config and confirm these exist in your version and are set correctly:

• commandUseWorldEdit → false
• pasteNbtRestoreBehavior → None

If those option names are missing from your Litematica build, your version is too old for the Server Paster mod to hook into. Update Litematica.

Third: the block-state skip rule

Even with everything configured, Litematica will not re-paste tile entity data onto a block whose state already matches the schematic. If you pasted once and NBT is missing, break the affected blocks and paste again.

Fourth: permissions and chat

• Confirm you can run /setblock and /summon manually.
• Check that no chat plugin is filtering or truncating long messages — some anti-spam plugins break the custom packet.
• Look at the server console for command errors when you paste.

Work through these in order; the vast majority of "not working" cases are one of the first two.