As of CreativeCore_v1.10.45_mc1.12.2 + LittleTiles_v1.5.0-pre324_mc1.12.2, when using the Littlehammer to carve into a block, the BreakEvent is called after replacing the block with a littletiles:blocklittletiles, while forge will call this event before doing so.

This prevents to filter properly the cancel decision.

Issue is no longer reproduced with CreativeCore_v1.10.58_mc1.12.2 + LittleTiles_v1.5.8_mc1.12.2, so I guess that did the trick.

Very good to hear! Thanks for testing and reporting this issue!

In theory the event is fired before anything is edited. But the client performs the action anyway. Only the block is being converted before the event, not sure if that made a difference. Changed it now. Also the server should send a reset packet for the player.

New version is out, can you test if anything has changed?