Npc's Dissapearing when i reload server

[joelestral]

i have adding citizens to my server follwing the installation guide, and have made three npc's as you do, although, when i reloaded the server, they all disapeared with their profile in config still. When i make a new npc, it seems to still count the other id's and say, if the ID's of the dissapeared npc's were 123, then when i would create it again, it would be 456.

Please tell me what i have to do to solve this issue