Error in write to data store entity : " Problem with task"

Can you go to process details and show us the error message.? if possible share the snap.

Also data in process variables is not getting written to the database table

I think you are using write to mulitple datastore entities smart service.  from the error it looks like you have not configured this node properly. Try to check this node configuration, like what are the entities you are writing to and what are the values in entityData parameter.

you can also go through below link

https://docs.appian.com/suite/help/21.4/Write_to_Multiple_Data_Store_Entities_Smart_Service.html

Ok Thanks !