That bug was happening to me last year. Later it seems to have been fixed and you are seeing it again.
Unless you are a programmer and can get into the code, I'd wait for the new version to see if they fixed it (again.)
In other words, I doubt it's caused by you or your machine.
Bob
Using Firefox 25.0.1 on a Mac running Lion. When I get an e-mail with a link in it and click the link, if Firefox is already running the linked page opens without any problem. If Firefox is not running, clicking the link will launch Firefox but it only opens my home page. I have to click the link a second time to get the linked page to open. This happens with every link.
Any ideas what might be causing this and how to fix it?

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