3 Answers

You may be trying to install the wrong version for your operating system. Use this link > http://get.adobe.com/flashplayer/otherversions/ 

i am getting all the time this kind of errors

for itunes also when i try to download it :/

This Connection is Untrusted

You have asked Firefox to connect
securely to swdlp.apple.com, but we can't confirm that your connection is secure.
Normally, when you try to connect securely,
sites will present trusted identification to prove that you are
going to the right place. However, this site's identity can't be verified.

What Should I Do?

If you usually connect to
this site without problems, this error could mean that someone is
trying to impersonate the site, and you shouldn't continue.

Technical Details

I Understand the Risks

If you understand what's going on, you
can tell Firefox to start trusting