If the client is facing below error while edit booking in Front desk, Then you can download the tool from below link and run it at client side on the server machine in order to resolve the DB null error and then # mark on the details in the bottom.
Tool link:-
https://ezeenextgen.s3-us-west-2.amazonaws.com/download/DataDoctor/Datadoctor_20171213_#%20count%20error%20while%20booking%20edit.zip
After running the tool on the server machine in eZee path folder, restart eZee front desk and check the particular booking.
Thank you.