I spawn the slapper and add the command and it works, but a few hours later , slapper disappear. Can you help me to fix it?
I've actually had this issue as well, so I can vouch for the fact that it does in fact happen on PMMP v3.11.6 with Slapper v1.5.2 (latest version).
Simple Answer: Sadly, you can't fix it, because the entity nbt was either deleted (some how some way), or not saved/loaded properly by the plugin itself. I had this issue before and this is what caused it: - Entities are loaded to memory in pocketmine and saved on close or level save, and because slapper saves entities to levels with NBT telling slapper to register that entity as a "slapper" it relies on the level data to generate. So if the server's main thread (some how, some way) was killed externally (as in my case). It leaves the level files without nbt data because pocketmine did not get the chance to save the nbt before the thread was closed, again I'm not an expert at this but this was my issue with it. - If someone completely knowledgeable is reading this and I am completely wrong please do not send hate, I am just sharing what i debugged from my personal experience .-.