Hi,
Never had this:
Boinc launches and the tasks show up as running, yet nothing progresses and Boinc sits at 0.4% Cpu usage... ;-(
Tried a reinstall, no change...

Here the Log:

Sam 12 mar 12:42:20 2016 | | cc_config.xml not found - using defaults
Sam 12 mar 12:42:21 2016 | | Starting BOINC client version 7.6.22 for x86_64-apple-darwin
Sam 12 mar 12:42:21 2016 | | log flags: file_xfer, sched_ops, task
Sam 12 mar 12:42:21 2016 | | Libraries: libcurl/7.39.0 OpenSSL/1.0.1j zlib/1.2.5 c-ares/1.10.0
Sam 12 mar 12:42:21 2016 | | Data directory: /Library/Application Support/BOINC Data
Sam 12 mar 12:42:21 2016 | | OpenCL: Intel GPU 0: HD Graphics 4000 (driver version 1.2(Dec 17 2015 21:11:48), device version OpenCL 1.2, 1536MB, 1536MB available, 160 GFLOPS peak)
Sam 12 mar 12:42:21 2016 | | OpenCL CPU: Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz (OpenCL driver vendor: Apple, driver version 1.1, device version OpenCL 1.2)
Sam 12 mar 12:42:22 2016 | | Host name: Mac-mini.local
Sam 12 mar 12:42:22 2016 | | Processor: 8 GenuineIntel Intel(R) Core(TM) i7-3720QM CPU @ 2.60GHz [x86 Family 6 Model 58 Stepping 9]
Sam 12 mar 12:42:22 2016 | | Processor features: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clfsh ds acpi mmx fxsr sse sse2 ss htt tm pbe pni pclmulqdq dtes64 mon dscpl vmx smx est tm2 ssse3 cx16 tpr pdcm sse4_1 sse4_2 x2apic popcnt aes pcid xsave osxsave tsctmr avx rdrand f16c
Sam 12 mar 12:42:22 2016 | | OS: Mac OS X 10.11.3 (Darwin 15.3.0)
Sam 12 mar 12:42:22 2016 | | Memory: 16.00 GB physical, 593.73 GB virtual
Sam 12 mar 12:42:22 2016 | | Disk: 1.12 TB total, 593.49 GB free
Sam 12 mar 12:42:22 2016 | | Local time is UTC +1 hours
Sam 12 mar 12:42:22 2016 | | VirtualBox version: 4.3.28r100309
Sam 12 mar 12:42:22 2016 | climateprediction.net | URL http://climateprediction.net/; Computer ID 1336180; resource share 100
Sam 12 mar 12:42:22 2016 | Milkyway@Home | URL http://milkyway.cs.rpi.edu/milkyway/; Computer ID 537576; resource share 100
Sam 12 mar 12:42:22 2016 | SETI@home | URL http://setiathome.berkeley.edu/; Computer ID 7095842; resource share 200
Sam 12 mar 12:42:22 2016 | SETI@home | General prefs: from SETI@home (last modified 10-May-2015 18:31:50)
Sam 12 mar 12:42:22 2016 | SETI@home | Host location: none
Sam 12 mar 12:42:22 2016 | SETI@home | General prefs: using your defaults
Sam 12 mar 12:42:22 2016 | | Reading preferences override file
Sam 12 mar 12:42:22 2016 | | Preferences:
Sam 12 mar 12:42:22 2016 | | max memory usage when active: 8192.00MB
Sam 12 mar 12:42:22 2016 | | max memory usage when idle: 14745.60MB
Sam 12 mar 12:42:22 2016 | | max disk usage: 610.75GB
Sam 12 mar 12:42:22 2016 | | max CPUs used: 6
Sam 12 mar 12:42:22 2016 | | don't use GPU while active
Sam 12 mar 12:42:22 2016 | | (to change preferences, visit a project web site or select Preferences in the Manager)
Sam 12 mar 12:42:22 2016 | SETI@home | Task 24my11af.15765.23380.11.38.178_1 is 0.07 days overdue; you may not get credit for it. Consider aborting it.
Sam 12 mar 12:42:22 2016 | | Suspending GPU computation - computer is in use

Sam 12 mar 12:42:22 2016 | | Reading preferences override file
Sam 12 mar 12:42:22 2016 | | Preferences:

Sam 12 mar 12:42:22 2016 | | don't use GPU while active

Sam 12 mar 12:42:22 2016 | | Suspending GPU computation - computer is in use

Your preferences are set to only use the GPU when the computer is not in use (aka idle). So any tasks running on the Intel GPU will suspend as long as you're on the keyboard or mouse.

From the messages we cannot see if you also allow the CPU to be used.

Furthermore, you have at least one task that's past the deadline and still not finished:

Sam 12 mar 12:42:22 2016 | SETI@home | Task 24my11af.15765.23380.11.38.178_1 is 0.07 days overdue; you may not get credit for it. Consider aborting it.

This may cause BOINC to stop asking for work, because there is no sense in asking for work if the system is not capable of returning it within the deadline. So either abort the task or finish it, then report it and see what BOINC does next.

If it's allowed to use both the CPU and GPU and ask for work for both, that'll show.

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