After updating to version 1.15.1 my server started to shut down on its own, after analyzing the logs I realized that the villagers are being responsible .... the bottom follows a link from the log https://pastebin.com/YSdZ9g7R Help Plis!!!
Similar to as @Maxx_Qc suggested ... The affected villager is identified in your server log, which happens to be close to 'rogerbraw's and 'ReOffSpark6's location. Spoiler Code (Text): Details: Entity Type: minecraft:villager (net.minecraft.server.v1_15_R1.EntityVillager) Entity ID: 395 Entity Name: E9 Entity's Exact location: 76917.60, 97.00, 61098.70 Entity's Block location: World: (76917,97,61098), Chunk: (at 5,6,10 in 4807,3818; contains blocks 76912,0,61088 to 76927,255,61103), Region: (150,119; contains chunks 4800,3808 to 4831,3839, blocks 76800,0,60928 to 77311,255,61439) Entity's Momentum: 0.00, -0.08, 0.00 Entity's Passengers: [] Entity's Vehicle: ~~ERROR~~ NullPointerException: null Stacktrace: at net.minecraft.server.v1_15_R1.World.a(World.java:718) at net.minecraft.server.v1_15_R1.WorldServer.doTick(WorldServer.java:395) -- Affected level -- Details: All players: 5 total; [EntityPlayer['rogerbraw'/388, l='mundo', x=76923.76, y=97.00, z=61088.16](rogerbraw at 76923.76486892274,97.0,61088.15988119781), EntityPlayer['abryel'/451, l='mundo', x=37717.74, y=63.00, z=80890.85](abryel at 37717.74125670273,63.0,80890.84947378379), EntityPlayer['Artic'/565, l='mundo', x=21938.09, y=64.17, z=99576.37](Artic at 21938.087761637813,64.16610926093821,99576.36571943811), EntityPlayer['TFrastBR'/874, l='mundo', x=41805.42, y=79.75, z=99147.14](TFrastBR at 41805.41849494529,79.7531999805212,99147.13944029389), EntityPlayer['ReOffSpark6'/664, l='mundo', x=76924.98, y=97.00, z=61088.72](ReOffSpark6 at 76924.980313448,97.0,61088.723350871616)] Ensure that 'rogerbraw' and 'ReOffSpark6' does not join the server, and remove the offending Villager. You may then have 'rogerbraw' or 'ReOffSpark6' rejoin to see if the problem is resolved. As md_5, suggested, a plugin may be the initial cause of the problem, and may replace the deleted Villager! In which case you will need to identify the offending plugin and find a solution for why it is going wrong.