STAAD V8i - SS6 - Missing plate element section property and material setting on large model

Hi,

I have asked this 5-6 years ago on this platform to no avail.I even opened a thicket and was told that the developers are looking at the issue, but now its been ages and i'm still experiencing the same issues on large models? 

Please see attached .std file, its a typical model with only one type of plate element and column type. If you open the model you will see many plates with missing property, but these were all previously assigned on the graphic editor. Even if you select plate with missing property and assign all , save the file and reopen it you will still have many plates with missing property?  

The above obviously don't happen on smaller models, but for larger model version SS6 is really unstable or unusable.

.std file 

https://drive.google.com/open?id=0By6OZXncXf9KQ0QxZF8xd2tQMXc