Difference in way of working N:M relations between entities in Mendix 7.9 and later versions (e.g. 7.23.26)

I have an old application running in Mendix 7.9 which need to be upgraded to the LTS Mendix 9 version. Before that I need to go to the LTS of Mendix 7 (7.23.26) When I upgraded to 7.23.26 I noticed that some functionality which uses N:M (*:*) releations in the model, are not working anymore. When I delete those relations and newly create them with the same settings and name, the functionality is restored, but in the database the id of the association is changed and therefore the actual association in the DB is lost...so not the correct way of solving this. As I can remember, in the older version of Mendix, N:M releation where actualy two seperate 1:N releations, visualized in the modeler on top of each other as N:M relations. Somewhere between 7.9 and 7.23.26 this technical implementation had changed to an actual N:M relation. So I can imagine that my functionality in my old 7.9 version is not working anymore. Question is: Is there a standard solution to resolve this technical change or do I need to create 'in between'-entities for each situation and merge the N:M releations to those entites before I upgrade? (and after upgrade revert the change to the new technical implemantation of the N:M relations in the model)
1 answers


I’m not aware of such an implementation change within Mendix 7. Maybe a different issue? What exactly is not working anymore?

regards, Fabian