It has been reported that the Old View of the Contacts page generates an "Object reference not set to an instance of an object" error when clicking the Change button in an attempt to edit the first contact record in the list of contacts. This has been occurring since the 2/2/2018 version of Aeries, however not all customers are experiencing this issue.
As an immediate workaround, the user may use the New View of the contact page to edit contact records. Additionally, clicking on a contact other than the first record, and then clicking back to the first record will allow the Change button to function normally in the Old View. If only a single contact record exists, clicking Add then Cancel is also a workaround.
Programming is investigating this issue and is currently working on a fix.