After migrating to 5.6 I find I can not open any entries I have in Parties.
I can see the list of Parties but double clicking on any of them does not change to the form.
I also can not add any new Parties although I can duplicate existing entries.
No error is displayed.
Was some new field added for Parties in 5.6 which may be empty or not populated correctly?
I guess you have custom module that modify the party form which is not compatible with series 5.6.
No, I do not have any custom modules.
I will continue to investigate.
I have not been able to find the reason for this. Enabling a high level of logging from trytond shows no errors. Is there any other debugging method I can use to see what is going on ?
Check errors on both side the server and the client.