synching erd model loses foreign key links

[jason w]

I have an existing database where the design is frequently updated (new tables, addition of columns, removal of tables/columns, etc). I initially created the database writing ddl code and saving it as a script file. I’ve made several updates to the script and reran the script to recreate the db for the updates. I am using the workbench diagram/modeling tool to generate EER diagram. 

So i have the existing model (mwb file) from before these new updates. All fk links are connected. When i go to synch model with my new db updates, for some reason a lot of fk links are gone/removed. Even with tables i made no changes to. In my scripts and the db, the fk constraints are there, but the model doesn’t recognize them or something. When i go thru the synch model process I am choosing “update model” during the model and db differences screen for the changes it recognizes. But even for some tables that didn’t change, the fk link is lost! And i can’t figure out why. Anyone experienced this behavior?