A list view that shows accounts with related opportunities.

HI,
How do I fix this? - Validation Errors While Saving Record(s), i got below this error

user is getting while converting lead ,then i will gettine this error ,There were custom validation error(s) encountered while saving the affected record(s). The first validation error encountered was "Opportunity Owner can not be a Partner User".


Regards,
VIswa

What is salesforce developer platform1 means is it previous DEV401 exam.What is present Admin 201 exam is it app builder or salesforce certified administartor exam.
Thanks