I recently got my computer re-imaged. Everything was working fine on Yosemite until about an hour ago when my Wi-Fi abruptly disconnected. The AirPort icon gave me the rainbow spinner, so I restarted my computer. The Wi-Fi issue disappeared upon restart, but Safari (which had been open as my default browser before the restart) now refuses to open. When I click on the app in my dock, applications folder, Launchpad, and anywhere else, it doesn't open. The icon doesn't bounce, and the app won't work even when I click on a link in an email or something. There's no crash log. Any fixes for this?
I would check Activity Monitor while you are clicking the Safari icon. See if there are any processes like "Safari" or "Safari Web Content" that is showing up, and see if there is a red "not responding". This probably will not happen if the app does not even bounce, but it's worth a try. You can also try basic things like right clicking, clicking "Show all windows" or going to Options and clicking asking to this desktop. Also, have you been working with multiple displays recently? The safari window may be "stuck" on the other display, so you should check it out by plugging any back in.
Not sure if this will help - but I had a (sort of) similar issue.
When I opened Safari, it would sit in the dock and nothing would happen. No window, nothing. I was perplexed.
What I didn't ever realise is that there was no window defined.
I right clicked the icon in the dock and selected 'New Window'.
A massive Homer Simpson 'Doh!' ensued.