Error of connection

Hello, We have currently an application which is connected to base SAP Business one via the SAPbobsCOM.Company object. This application has functioned for several months in a correct way. After a change of licence server, the application refuses to be connected with the error message according to. -2147024891 - - refused Access.

We have applied the note 833798 but without success. Cordially. S. Provost

Please Help