In the cWebSessionManagerStandard (which you probably use) Ln56 -> Send Request_Save of hoSessionDD
You would need to fill phoSessionDD of your oSessionManager with your WebAppSession_DD-Object containing the right structure (Server set).
I recommend a subclass with Construct_Object having
Code:Forward Send Construct_Object Get phoSessionDD to hoSessionDD Property Handle phoContCamType 0 Get Create (RefClass(cContCamType_DataDictionary)) to hoContCamTypeDD Set DDO_Server of phoSessionDD to hoContCamTypeDD // or vice versa if your session table is the father. Set phoContCamType to hoContCamTypeDD
This should set the structure.
Then saving should work because the DD is there.
P.S: I am using DF 18.1