It is possible to connect a 4D Client and 4D Server that are on different builds of long term releases (i.e. v18.1, v18.2, v18.3). When trying to make a connection between different major versions (i.e. v17.x and v18.x) or between feature releases (i.e. v18.1/v18R2 and v18R3), the error below appears.



Although inter-build connection is possible, it is highly recommended to have 4D Client and 4D Server communicate on the exact same 6-digit build number. This is because there are small internal differences between each build of 4D. Although these changes are small, mixing further apart builds can cause incoherence. Mixing and matching different builds of Client and Server may produce unexpected behaviors or errors that would not normally occur when using the same build of Client and Server. Therefore, it is highly recommended to use the same build of Client and Server to maintain integrity.