Error "Save rejected because field (Probability) is defined as mandatory by key user." occurs, however, when opportunity is set to Lost status, it's system standard behavior that Probability will be set to 0% automatically (for this behavior, you can refer to KBA 1925772).
Since SAP Cloud for Customer 2011
Reproducing the Issue
The standard field Probability is defined as Mandatory using KUT tool.
- Open an opportuniy which status is not Lost, and the Probability field has value in it.
- Click on Actions >> Set as Lost
- Save. Then you will see the standard field "Probability" is set to 0%, and the error occurs.
This error is an improvement since 2011 upgrade. Basically when Probability is set as mandatory field then it logically shall not be 0. But here in this case when Opportunity Status is set to Lost, value of probability is set to 0 and also it is mandatory.
You can simply write a minor rule to achieve this. Rule can be like - When Opportunity is set to Lost then Probability shall not be Mandatory.
Code can be: Root.LifeCycleStatusCode != '5'
Code 5 means Lost. Assign this rule to Probability field. By this we can say that Probability is not mandatory only when status is set to Lost and in other cases it shall be true.
Opportunity, Probability, Lost, Mandatory , KBA , AP-RC-UIF-FLX , Page Layout & Key User Configuration , Problem