I am having the same issue. I too upgraded from 4.2.2 to 5.
When I create an encounter the normal way, I get a blank page/tab when I try to access the fee sheet.
However, if I create the encounter via the @arrived method, it works fine.
I have found that for every encounter created via normal methods, the "provider_id" field of the "form_encounter" table of the database defaults to "0".
If I manually enter the correct provider ID, it all works.
When using the @arrived method, the correct provider is placed in the "provider_id" field.
The reason I looked into the form_encounter table was that randomly I will be able to see a fee sheet and make some entries. But when I tried to save it it would blank-out the whole form. I found that if I was able to access the fee sheet and immediately select the provider (because it was not populated) then save the form, I could re-open it and continue making entries.
I hope this helps.
PS: I am running Linux Mint 18