You complete your database, and the company begins using it. shortly afterwards, two gearup buyers, cora and owen, work together on a sale from a supplier called tennissource. both come to you complaining that their entry into the "supplier history" part of the database is not showing up. instead, the field reads "invalid entry." what is most likely the problem?

Multi-user issue

Explanation: A database management system scheme can have multi-user issue when the designing of the system is not made properly. The multi user issue rises when the users concurrently access the data from the database and related error get invoked due to some reason like  repeatable reading issue, serialization, etc.

The reading problem is usually can be related to reading of the database in  uncommitted manner, uncommitted reading, repeatedly reading etc.Thus, Cora and Owen are accessing the database concurrently which can create multi-user issue.

this does not make any sense.. i you can reword that i can maybe you