Transfer applicant need help

I sent online application ( transfer application) 1 month ago. Couple days ago, I visited myuw site to check my application status and I got this one mgs:
After giving your application to the UW Tacoma an initial review, we have determined that one or more documents, supporting materials, or additional information are required before further reviewing your application. All required materials must be postmarked by the application closing date for autumn quarter 2015.
I already sent to uw my current college transcript and shoud I send to uw my official high school transcript? And what happen next?
IF I have to send my high school transcript, can I send it after Mar 15,2015?
This is my first time make transfer to uw. Really need help.
Thanks all.

I think you need to ask UW directly. They can give you accurate, precise information.