Some of our customers have experienced that the customizedFields property for customers and contacts endpoints is not working.
If you experience this as well, please contact us and we will make sure this feature is enabled properly for your company.
As per today, there is no community area for the Advisor software.
If you have any questions regarding the Advisor API, please contact the support at API_Advisor@visma.com
For documentation about the API visit the Advisor API site