From one version to another (eg 5.0.1 to 5.1.0) you could have several database schema updates.
There is no list of impacted fields so the first thing you have to do after an upgrade is to refresh all views (Admin/View Management/All View -> button Refresh). By doing this any manuel modification will be lost.
If you still have error with field (missing, wrong name, etc) you have to create a fresh install and to compre both databases.
Regards.