Ex4100 / OS5 / Full Test / Stuck at 90% after 8 hours

Hello,
WD My Cloud Ex4100.
I launched OS5 / Settings Utilities / Full test.
Now, the System Diagnostics - Test in Process bar seems to be stuck at around 90% after 8 hours.
The WD My Cloud Ex4100 seems inactive / CPU is 0%
My Ex4100 is new, there is no data in the server.
But I don’t want to use it without making this test first.
Please advise.
Thank you.

More details hereunder:
I just bought WD My Cloud Ex4100 56 to (4x14to).
Did full update: OS5, firmware
Everything working fine.
I launched Settings Utilities / Full test.
“System Diagnostics” - Test in Process seems to be stuck at around 90% after 8 hours.
The WD My Cloud Ex4100 seems inactive / CPU is 0%
I rebooted
Launched again Settings Utilities / Full test.
And again “System Diagnostics” - Test in Process seems to be stuck at around 90% after 8 hours. The WD My Cloud Ex4100 seems inactive / CPU is 0%.

@AnB The following article may help resolve your issue.

Thank you very much - checking.

OK. For information, Full system check took 25 hours 25 minutes to complete.