Flash Errors #1001 and #2034

I am very new to Flash Builder and I am getting the following 2 errors in Firefox and IE when I run my programs.

1. .swz failed to load. Error #2034

2. Flex Error #1001: Digest mismatch with RSL. Redeploy the matching RSL or relink your application with the matching library.

Can anyone explain the meaning of thesse errors and how I could go about debugging them?

I am using Builder 4.6

Thanks