The capacity of text fields is set in an object type's definition in the catalog. Access the catalog, select the node type or link type, then click on the text field in the Field inspector window. In the Text Field Inspector, change the Bytes to be longer than the text you want to enter the field. Maximum text field capacity is 6,000 characters.
Text field will not accept more than 40 characters
(Legacy KB ID CNC TS33178 )