Can a professor post a grade online and then change it? Can a University professor post a grade on web-campus or blackboard and then change the grade the next day? Yesterday I received a B and today I it had been changed to a C... C's do not pass the class in the masters program.
In the US, universities generally have a policy that describes under what conditions a professor can change a grade that has been officially posted to the student's record.  

For example, in my university, the official policy is that an instructor may change a final grade that has been officially posted to the student information system if there was an error (e.g. in the calculation of the grade) or if the instructor overlooked some work that the student submitted1. The web interface asks me to supply the reason when I submit the grade change request:



When I submit a grade change request after grades have been posted, it goes through another layer of approval (department head) but barring exceptional circumstances, these changes are routinely approved.

"Intermediate" or "unofficial" grades (e.g. grades that are posted in Blackboard but not in the official student information system, midterm grades, grades on assignments that aren't the final course grade, etc.) typically are not subject to those rules, and can be changed more easily.



1 Although students persist in asking me to change their grades for all kinds of other reasons.