RC error code

Using MDM 5.5 SP5, while using Import Manager for Importing xml,

one of the repositories gets this error-

"Import failed. Partial Set failure with RC error code = <0x84020020> for record number 0 through 9"

For all other repositories, importing xmls is successful.

Secondly, I am unable to add a record in data manager.

Following Error-

Record cannot be saved.

"No query results returned, Version 5.5

SP5 (5.540.83)