[08:00:51] [Server thread/INFO]: [WarpPortals] Enabling WarpPortals v5.6.3
[08:00:51] [Server thread/INFO]: [WarpPortals] Error in Portal's data file with String "tpCoords: (Survival,-0.5810753716858538,72.0,257.3522491644574,11.849996,-5.7816504E-7)".
[08:00:51] [Server thread/WARN]: [WarpPortals] WarpPortal data loaded using the old data-structure. The next save will migrate it to the latest portals.yml version.
It looks like its a data error with the plugin.
I suggest using Multiverse-portals for warping portals instead and you already have Multiverse-core so you can easily add it.
Here is the link: https://dev.bukkit.org/projects/multiverse-portals