You can check the Note at the following link :
Following is the text of the Note :
When trying to add a new price list or update an existing price list you might come across with an error message "Variation between number of price lists and number of price lists for items [Message 3506-9]"
Note: This situation can happen during import data from external
application and not directly from B1.
Price list, update, add
Reason and Prerequisites
In order to fix the corruption that was caused prior this issue
Please run the select query above to determine whether your
databse is affected, please contact the global support center
Select * FROM ITM1 T0
Left JOIN OITM T1 ON T0.ItemCode = T1.ItemCode
Where T1.ItemCode is NULL
And T0.Itemcode not in (Select itemcode from OINM)
SAP Business One Forum Team