hallo i have this same problem :
whit extDB2
my run comand: ./arma3server -Mod=@life_server -Mod=@extDB -port=2302 -noCB -exThreads=4 -config=server.cfg -cfg=basic.cfg -name=arma3 -autoinit -loadMissionToMemory
serwer runs on Ubuntu Server 14.04 "Trusty Tahr" LTS (64bits)
MY RPT LOG:
this same mission and life_server on nitrado host works extDB2