Для РПГ 512MiB Это очень мало. Поставьте выделение оперативной памяти на авто. Если не поможет, включите режим откладки в лаунчере и скиньте сюда ошибку.
# An error report file with more information is saved as:
# C:\Users\User\.cristalix\updates\RPGNextGen\hs_err_pid11484.log
allocate 756632 bytes for Chunk::new
ngScreenRenderer.run(MinecraftDisplayer.java:334)
# An error report file with more information is saved as:
# C:\Users\User\.cristalix\updates\RPGNextGen\hs_err_pid11484.log
allocate 756632 bytes fo# An error report file with more information is saved as:
# C:\Users\User\.cristalix\updates\RPGNextGen\hs_err_pid11484.log
allocate 756632 bytes for Chunk::new
# An error report file with more information is saved as:
# C:\Users\User\.cristalix\updates\RPGNextGen\hs_err_pid11484.log
#
# Compiler replay data is saved as:
# C:\Users\User\.cristalix\updates\RPGNextGen\replay_pid11484.log
OpenJDK Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release
java.lang.OutOfMemoryError
java.lang.OutOfMemoryError