I'm having this problem too, I reinstalled boinc which didn't help. The tasks its stuck on now are: OET1_0000625_xMBGP-F_rig_64648_1 and OET1_0000625_xMBGP-F-rig_64653_1
This is on a moto e phone (android) which has worked fine on other tasks. Ebola is running fine on my windows 8 laptop.

That was my thread. The job eventually finished, but my wingman never responded. Last I had seen, the job was re-sent to another device and when I went to check again it had disappeared. So I am unaware if it validated or not.

The staying at 100% for multiple hours is of -Normal- expectation [On Android], though we don't know what it's doing [hot air processing maybe ;>]. At 99.9% the 8th and final checkpoint is done and most jobs conclude in a jiffy, the longest 'seen' sitting at 100% was for 9 hours. I've confirmed if restarting these [taking long at 100%], they resume from 99.9% and do the same long 100% routine again... it's somehow needed. Not like there's nothing being done.

Never have observed it on Windows/Linux [when randomly looking in on the client health], ... it's not what I spend time looking for, and since the jobs finish and validate, it is not concerning me, don't even know if the 100% time is fully included in the Elapsed/CPU time as reported on the Result Status page. Anyone looked at that? If it is, it's a non-issue, but for testing patience when it occurs.