After installing Dec 2016 update I cannot see Stages Bar on Lead and Opportunity

Hi,

after the installation of Dec 2016 update I cannot see Stages Bar on Lead and Opportunity.

I'm a System Administrator user.

I can activate Processes, I see them in the Processes list, I can edit them.

If I create a new Opportunity or Lead, I see Stages Bar, but if I close it and reopen, Stages Bar disappears.

Also, if I open an existing Opportunityor Lead (that has the BPF active), I don't see the Stages Bar.

!?!?!?!

Very unusual!

Any advice? Is there a log that I can read?