why the fuck it's in download link ? do u think someone will download something by user who got 1 post ?
well personally i dun give single fuck about viruses cuz i've fun eliminating them so anyway it's clean
about ur problem
this is cause because of wrong configuration between server and database , check the configuration files and search whole source for root (you should find everything related to it) , also make sure in the very first place that you got a database with tested connection
first time i was trying to setup a server i came here asking a stupid question like that , and year ago i faced same problem cuz i didn't do it on my own which was easily to forget what should i be doing , after spending 6 hrs of facing all kinds of errors and problems i can solve them all , so i really think you should spend time trying and searching for better understanding