The cause of the issue seems to be that the plugin stores playerdata in uuid format. when a bedrock player joins they have a prefix since they can use the same names as normal players so for example if a bedrock player was named tobi the person would be given the name .tobi in-game (. is the prefix in my case).
I think that maybe since the plugin cant find the uuid of the person it probably tries to add an empty object & throws a null error? I did notice if I go into the data.yml file & remove the last line thats added that will fix it.
Not sure how to solve this issue, maybe make it so it can store users with a certain prefix (like . in their name since java users cant do that) by name instead of uuid? Though I can see the downsides to it, well its just annoying that the whole plugin breaks because of it.
ghost
commented
3 years ago 
Realizedd
The cause of the issue seems to be that the plugin stores playerdata in uuid format. when a bedrock player joins they have a prefix since they can use the same names as normal players so for example if a bedrock player was named tobi the person would be given the name .tobi in-game (. is the prefix in my case).
I think that maybe since the plugin cant find the uuid of the person it probably tries to add an empty object & throws a null error? I did notice if I go into the data.yml file & remove the last line thats added that will fix it.
Not sure how to solve this issue, maybe make it so it can store users with a certain prefix (like . in their name since java users cant do that) by name instead of uuid? Though I can see the downsides to it, well its just annoying that the whole plugin breaks because of it.