STAAD ERROR MESSAGE

Question

Dear Sir/Sirs, 
 
 Am new to STAAD Pro. I have designed an intake using plate model. Assigned loads. When i try to analyse following error appears. 
 PRIMARY LOAD CASE CAN ONLY BE ADDED IF SET NL COMMAND IS USED. 
 How can i rectify. Please help. 
 
 Reg 
 Varad

Shany · Accepted Answer

When a model contains more than 25 load cases, with some being solved using one set of conditions and others being solved with another set of conditions, a command known as "SET NL nn" is required where nn is a number which is at least equal to the number of load cases. 
 In this case, this condition is achieved by the CHANGE command that you have used after every analysis. As it turns out from the STAAD model you have attached, the total number of load cases is beyond the default number of load cases the space has been reserved for. Hence, I have used the SET NL command. This command instructs the program to set aside additional memory space for information to be added later. 
 Open the Staad Editor File, and before the JOINT COORDINATE command line, add the command SET NL 100 (for this model I have added 100)

Shany · Answer

Please send us the model.

Shany · Answer

The program is not able to see the number of load cases that has been specified beyond the CHANGE command. Hence, it reserves space for a default number of load cases. If the specified number of load cases is beyond the default number, the program would not be able to accommodate that. I presume,in your model, the total number of load cases is beyond the default number of load cases the space has been reserved for. Hence, you need to manually reserve the space for the existing number of load cases using the SET NL command.