What is ePhaseHeader test and how do I mitigate this?
It's not necessarily something you need to change or mitigate. Does the same thing happen each time you run a scan? If so, try looking at the WAS scan report and review QID 150018 to see if more details are provided.
If that's not useful, open a case with Qualys Support and they can help figure it out. To open a support case, log in and choose Help -- Contact Support.
Retrieving data ...