QUESTION:  Getting "Object reference not set to an instance of an object" error when generating Deflection Check Report.

ANSWER:  To generate the Design > Design Check > Deflection Check Report one needs to make sure of two things: One has a deflection load group and Deflection option is checked in Design options.

• Make sure you have the Deflection Live Load under the Live Load group.  If you don't have one please create one with the option "Only for LL Deflection" toggled ON and you have selected the desired Live Loads:

• Run the Analysis with Live Load toggled ON
• In the Design Results/Reporting dialog open Design Options and toggle ON "Check Deflection based on Art. 2.5.2.6.2" and then Run Design Check.

• Then Open Reports > Design Check and run the "Deflection Check Report"