We’ve had some reports on the blog, and our QA team has confirmed that having the Firefox Adblock add-on enabled for the Hotmail site can make it impossible to compose or reply to a message in the full version. This does not affect Internet Explorer users or Firefox users who do not have the Adblock add-on. Depending on which Adblock filters you’ve created, you may or may not be affected.

The Hotmail team does cross-browser testing, including full Firefox testing – it’s important to us that you can get to your e-mail from anywhere. Unfortunately, it’s not possible to test every browser add-on, so sometimes things break, and thanks for your prompt reports of this problem!

While we do not condone suppression of advertising in our product (advertising does fund our product) we realize that users who have enabled this add-on may not understand why Hotmail stopped working.

We’re working how to mitigate this problem in a future release. In the meantime, if you’re having problems composing or replying in Firefox, you have two options:

1. Disable Adblock for Hotmail. You could also try tweaking your filters, but the foolproof method is to go to Tools --> Adblock --> and select “Whitelist this whole site.”
2. Switch to the classic version. This means clicking the “Switch to classic” link that you see in the lower left corner.

- Ellie Powers-Boyle, program manager