Hello Alberto ,
i guess the Problem was caused by an incomplete Update on your Note 5.
3 Solutions i can profer .
1. Go to Setting , baack up you Data and perform a Factory Reset . Check the Link below for Intructons .
https://www.youtube.com/watch?v=ctrQcAsEsOY
2 .The above Action should resolve the Problem .
If the Problem Persists , you may have to Flash the Phone with Samsung Smart Switch .
Download the Software for Windows or Mac Computer and follow the Instuctions .
-It is recommended that you restart your Computer after Download is complete .
- Turn on your Phone ( without Sim Card / SD Card , connect it to your Computer and allow the Drivers to be completelety installed . You may need to restart your computer again after Drivers are completely installed .
- Open Smart Switch , go to Backup and back your Data Up .
- Go to Upgrade / Recovery and flash the Phone .
- When the Process is complete , go back to Back up and Recover your Data .
Download Link https://www.samsung.com/us/support/owners/app/smart-switch
Video how to use Smart Switch
https://www.youtube.com/watch?v=1yXQUFrEWg4
3. Perform a Hard Reset . By hard reset , you may loose your Contacts ....but may be able to recover the ones stored on Google ....using thesame Google Account for the Note 5
See Video
https://www.youtube.com/watch?v=MsvrH-0UeAc
Post your result if this helps you , to help other Users .
Good Luck !!!