No offense intended, but are you using a Legit version of DW?
Yeah, bought from my school last year, i have the original code and download software purchased from my campus store.
Step 1: Close DW, Navigate to C:\User\Tyler\AppData\Roaming\Adobe\Dreamweaver CS5\en_US\Configureation\Workspace\ and delete that Classic.xml file
Re-open DW. DW should auto-create your Workspace layout XML file again. See if it works fine.
PROCEED TO STEP 2 ONLY IF STEP 1 DOESN'T SOLVE THE ISSUE
Step 2: Navigate to C:\Users\Tyler\AppData\Roaming\Adobe\Dreamweaver CS5\en-US\Configuration and delete the entire 'CONFIGURATION' folder. Re-open DW. DW should auto-create your configuration folder based on predefined layouts and config options. This will definitely fix your issue.
Reason for this issue: This issue would have been caused due to a malformed workspace layout configuration. That may happen due to customizations you may have done to the layout/ improper file permissions/ improper shutdown on Windows.
See if these fixes resolve your issue and post your results here.
First, I am not the original poster, but I got the same error. I own a a ligit copy of dreamweaver cs5. there was not "clasic.xml" but rather a designer.xml ... moved that, and it worked. thank you. You Rock.
I had exactly this problem and Step 2 resolved it! Thanks!
I had similar problem with CS4 version... Step 1 resolved the issue ..thanks a lot.