STAAD

I don't see any errors in your model. With respect to the warnings:

1) **WARNING - CHANGE COMMAND ISSUED WITHOUT SET NL DEFINED.

This warning says that you need to add SET NL command in your model before the joint coordinates in the input file. This Wiki explains this in more details: communities.bentley.com/.../what-is-the-set-nl-command

2) **WARNING-A MOVING LOAD THAT WOULD HAVE BEEN APPLIED BEYOND THE X AND Z RANGES
OF THE STRUCTURE HAS BEEN IGNORED. CASE= 17 WHEEL 5 OF 6

This warning says that some wheels of the moving load are out of the boundaries of the structure. This may not mean anything bad as long as you are aware of that. More details can be found in this Wiki: communities.bentley.com/.../warning-a-moving-load-that-would-have-been-applied-beyond-the-x-and-z-ranges

3) **WARNING- CONSECUTIVE ANALYSIS COMMANDS. ONLY FIRST USED.

This warning means that you have used several PERFORM ANALYSIS commands in a row, which is not required. I.e. in your input I can see such lines:

PERFORM ANALYSIS
PERFORM ANALYSIS PRINT LOAD DATA
PRINT MAXFORCE ENVELOPE ALL
PERFORM ANALYSIS PRINT LOAD DATA
PRINT MAXFORCE ENVELOPE ALL

Few commands just repeat itself and this leads to a longer analysis time. You should change such input to:

PERFORM ANALYSIS PRINT LOAD DATA
PRINT MAXFORCE ENVELOPE ALL