I worked out that the problem may have been that I was using the built-in compiler when compiling the UDF which was giving me a warning about not finding visual studio compiler. I am now not using the built-in compiler however now I get this error message 'fatal error C1128: number of sections exceeded object file format limit: compile with /bigobj'. This is because I need to include a large number of arrays with all the coordinates at each time step in the UDF.
I found a solution for this here - https://social.msdn.microsoft.com/Forums/vstudio/en-US/5043c081-a317-4528-a02d-d4b6e6d21543/problem-with-bigobj-when-compiled-by-other-software?forum=msbuild however when I try to include /bigobj in the makefile_nt.udf file I cannot save it as it gives me an error message about permissions.
This thread https://www.researchgate.net/post/Is-there-any-FLUENT-UDF-macro-to-replace-the-new-mesh-in-each-time-step summarises quite thoroughly what I'm aiming to do with prescribing the node position at each time step,