Hello people,
I am working from an older GAMS version (25.0.3) as I do not have the license for a newer version at my university. However, while I am trying to solve a MILP model with CPLEX it tries to solve with an optimality gap of 10%. However, after after 3 hours it cannot find a better optimalisation than a 47% gap compared to the linear optimalisation. It results in the following error: “Unrecoverable Error - (Integer Solution Available)”, in which the integer solution is at 47% relative optimality gap while I would like to limit it to a maximum of 10%.
The model consists of a supply chain with multiple optional routes to produce a product (with individual conversion factors), but cannot solve the model even though the supply input is more than sufficient to achieve the desired demand. As it is an older version of GAMS, I cannot find the error it displays and hope any GAMS wizard could help me out what the error tries to explain. Below, I have added a screenshot of the end result of the model, however I can give more information/screenshots if it helps so that someone knows a solution to this problem!
