You can't continue because ORA_HRX_GB_WAITING_DAYS certificate has payment dates outside the absence

Error- You can't continue because ORA_HRX_GB_WAITING_DAYS certificate has payment dates outside the absence dates.

Amend the absence or certification dates. (HRX_1562339)

We are getting this error, when trying to End Date Open ended Sickness Absence.

I know we can get this fix by Certification Void in Absence case. But, I would like to understand the cause of the Issue?

We are repeatedly facing this Issue, the users can't keep doing this process on everyone that this happens to.

Could you please help on this, the cause of error?