This is a rather old thread specific to the stand alone version of UE, not Data Bridge. Whatever the solution for the OP is most likely not related to your problem, even though the symptoms sound similar.
What version of Data Bridge do you have installed? make sure to install the most recent version 1.2.0, if you have a previous version installed, uninstall it from the extension manager then install the newer one.
after installing the newer version open DW and a php page to start the WebAssist installer.
after the WebAssist installer completes, make sure to restart DW.