[810143] Database error 50000: Creating a new master is only allowed on empty databases, while upgrading from version 8.0.2 to 8.1.5.

Hi,

[810023] Error during execution of statement:
set lock_timeout 10000
declare @ErrorMessage nvarchar(1000)= '50000'+char(9)+'2'+char(9)
if exists (select top 1 1
from sys.tables t
where t.type = 'U'
)
begin
select @ErrorMessage = concat(@ErrorMessage
, '#LDS#Creating a new master is only allowed on empty databases.|'
)
raiserror(@ErrorMessage, 18, 2) with nowait
end
set lock_timeout-1

While carrying out upgrade from version 8.0.2 to 8.1.5, via config wizard we are getting the [810143] Database error 50000: Creating a new master is only allowed on empty databases.

Our DB User has sysadmin and db creator access. 

Can anyone Please help us , as in what could be the wrong in here ?