Premise: This FAQ assumes your networking functioned properly and unexpectedly the client fails to communicate, out of the blue. You've established that your Internet is up from the device displaying the problem and you can reach the WCG forum and can log into the My Grid page.
General: Any action taken on the client to force communications with the project servers will try to open a link and keep it open for 5 minutes, even if in the Activity menu was set to Network Activity Suspended or the Preferences were set to network according a time limited schedule.
A few things that can be done to get going again:
- Open BOINC Manager Advanced View, visit the Activity menu and select Network activity always available,
- Open BOINC Manager Advanced View, visit the Advanced menu and hit Do network communication (Does not generate a message log entry!),
- Open BOINC Manager Advanced View, visit the Projects tab, select WCG and hit the Update button in left margin (Generates message log entries),
- Boot the computer so all gets fully refreshed.
If you made a change per point 1, change it back to Network activity based on preferences and do check that the website and local preferences relating to the daily network scheduling are still correct and behave according expectation.
Of course it does not harm to visit the support forums over at World Community Grid and review other topics related to communications & networking.