Updating could not be completed error

Hi Guys

I am getting below error in a confirmation .(CRM 5.0)

No activity prices exist for UK2011603/X-GS54 (Notification W BK
057)

No activity prices exist for UK2011603/X-GS21 (Notification W BK
057)

Updating could not be completed (Notification E S& 150)

I have updated the activity Pricing in KP26 and reprocessed the confirmation. This removed the error but after that confirmation gets a distribution lock at status level. When i removed the lock, error comes back. Also there is no issue in the queues as nothing is stuck. Please let me know how to removed this error.

Thanks

Prashant