I'm having issues with the BOINC Manager 5.8.15 and its inability to open a browser. This wasn't an issue with BOINC Manager 5.4.11 once I defined an environment variable named BROWSER.

I still have a BROWSER environment defined in my environment but the error popup claims that I don't have BROWSER defined. I was tailing my .xsession-errors file and I see the following message:

07:24:24 PM: Error: No default application can open .html extension

I'm starting the boinc manager from a shell script which looks like so:

#!/bin/sh
#
export BROWSER=/usr/bin/firefox
~boinc/BOINC/boincmgr