[HoloMobHealth] Unable to setup languages

[tncc2k]

Spigot 1.12.2
HoloMobHealth-2.2.2.2
Minecraft Vietnamese
HoloMobHealth-2.2.2.2 config default

[10:40:50 INFO]: [HoloMobHealth] Unable to setup languages
[10:40:50 WARN]: java.lang.NullPointerException
[10:40:50 WARN]: at java.io.StringReader.(Unknown Source)
[10:40:50 WARN]: at org.json.simple.parser.JSONParser.parse(JSONParser.java:79)
[10:40:50 WARN]: at org.json.simple.parser.JSONParser.parse(JSONParser.java:75)
[10:40:50 WARN]: at com.loohp.holomobhealth.utils.HTTPRequestUtils.getJSONResponse(HTTPRequestUtils.java:25)
[10:40:50 WARN]: at com.loohp.holomobhealth.utils.LanguageUtils.lambda$loadTranslations$3(LanguageUtils.java:91)
[10:40:50 WARN]: at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftTask.run(CraftTask.java:76)
[10:40:50 WARN]: at org.bukkit.craftbukkit.v1_12_R1.scheduler.CraftAsyncTask.run(CraftAsyncTask.java:52)
[10:40:50 WARN]: at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
[10:40:50 WARN]: at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
[10:40:50 WARN]: at java.lang.Thread.run(Unknown Source)

[LOOHP]

Seems like it is a connection issue when downloading languages from Mojang. Make sure your server can access this sites.
https://launchermeta.mojang.com/mc/game/version_manifest.json
http://resources.download.minecraft.net/