We are using a microsoft small bussiness server. One of our workstations get an mgrntw illegal operation error sometimes when doing an invoice in pastel premier. Does anyone know what can cause this problem and how can I fix it? The server run on windows 2000 and the workstations all use windows 98SE. This problem does not happen everyday. I formatted that computer, hoping the problem will go away but after 3 weeks it suddenly appeared again. I am not sure what version our mgrntw.exe is.