Sage VIP Classic and Sage VIP Premier

Good Day, How do GUID Codes on ESS become corrupt, as this has been happening to us for the last three months where I have had to go into ESS and merge the old GUID code for an employee to a new GUID Code? I have included a screenshot of the error…

Good day we had a method setup for unpaid leave to pull through to the payslip and hours screen and this method was created by a consultant when we started working on Sage Premier but now the method is all of a sudden not working anymore and this is…