Insert cannot be made due to collision while creating absence quotas

Hi Experts, We have two quotas 27 and 29 . When I am trying to create absence quotas 27 and 29 through 2006 for 2015 then I am getting error message “Insert cannot be made due to collision Message no. PG080”, We didn’t change any configuration but we are getting this error. Could you please let us know how to rectify this? Thank you all in advance. Regards, Vamshi