When I go to the spawn (where multiple ImageMaps are) I get kicked and I see this error in the console:

[Netty Server IO #2/ERROR]: java.lang.ClassCastException: java.lang.Byte cannot be cast to java.lang.Float

ImageMap: 0.5.0
Spigot: 1.14.3
Other Plugins: Worldedit, Worldguard, Vault, Multiverse, some custom plugins [they do not cause this error I checked that!]

Fixed:
--forceUpgrade