My pleasure Sanjay. There are a couple of things to look for to diagnose the Error.
First, be sure you are running the most current version, because no errors are reported in the most current version. If your service agreement is current, you can download and install the latest version from the website. If you are running a version earlier than 20.07.xx.yy, then it is probably not recognizing the SMALLDELTA portion of the PDELTA command. Just try deleting that one word, save, and see if that will run.
Next, be aware that the FLOOR load command will always produce a Warning, whether or not there is a problem with your particular use of the command. The Warning is there to remind us that the algorithm used to apply FLOOR loads can produce unexpected results if it is applied to an area that includes and inside corners. It is always best to visually inspect the loads that are actually applied by the FLOOR load command to ensure that they are as expected. If you ever have any trouble with it, the best thing to do is to break it into more commands that each apply to smaller areas within the model, and to make sure that each of the smaller areas is convex in shape.