Odoo errors are not that much verbose and self explanatory for a normal developer but if you understand how to figure the errors, easier to fix the issue.

For example, I run a new Odoo server with a backup a database and when click project, I got this error

odoo.exceptions.CacheMiss: 'project.task(6689,).stage_last_changed'

We can understand that stage_last_changed is a field in the model project.task and it i missing. This could be fixed by upgrading the corresponding module. But how do we know which module ? Well, one way to find it is that just search 'stage_last_changed' in the source code with your IDE and it will show you which module the code is mentioned. Once you found the module, then upgrade that module using Odoo UI.

Restart the Odoo and access the page which triggered the error last time, the error should be fixed now