1. Getting this error (0) very often!
- Receiving inbox notification that I received long ago!
- After end of a contract, I used to find the feedback visible on my profile within an hour but now they don't appear!
I am sorry you are experiencing technical issues. Does the error appear when loading the Messages or on other pages as well? Does it come up on any browser you try?
I will forward your report about issues with messages to the team.
As for the last point, it can take up to 12 hours for feedback to show once both parties provided it.