Permission problems help needed

so recently i updated my java version from 7 to java 8 to make a plugin work. but there came a problem some how ? idk why but all my kits whit special letters went missing for those how don't have op. when i returned to an old save where there still was java 7 and the kits where back for those are not op. If any one can help why does this happen and how to fix i'm using Essentials and Group manager