Yosemite Blues!

My MBP acting weird after upgrade. At home, it works great, but at work, it won't identify the server, and no network there.

We need more information. Read my sig link and post back.

re: Blues

Just upgraded to OS 10.10.
I use the MBP at home and at my job, which has a LAN with firewall. When I installed, I was at home, and I got the message that I needed to upgrade iPhoto if I wanted to use any of my 3,000 photos. I tried to update iPhoto, but got a message saying, "These apps were already assigned to another Apple ID, and they will be available in that Apple ID's Purchase List."
Later, at home, after several restarts, I was able to open iPhoto, and upgrades loaded automatically after that.
When at work, it would not access the internet with any browser, saying, it couldn't connect to server. When I looked at Network Diagnostics, Wi-Fi, Wi-Fi Settings, and Network Settings were green, but ISP, Internet, and Server were red. I went to "Go to Server", and the correct server was named, but it would not connect. Thanks for the help.

Wired or wireless, at each place? I couldn't tell from your post. iPhoto is not a problem now, right? So the one remaining issue is that it won't connect at work? Is that WiFi or wired? There are reports of some troubles with WiFi, but there doesn't seem to be any common cause that anyone has identified yet.

What MBP? If you are using WiFi, have you run the Wireless Diagnostics to see what the report says?

your mac is not FULLY recognizing the server at school, I have the problem with safari at the local library, do not go crazy, just find an alternative to using photos without iPhoto at school.
good luck!

Thanks! Apologies, it's wi-fi at both locations. Yes, iPhoto seems to be ok now, but I still need internet access.

So this isn't actually a Yosemite problem, it's a networking issue. You might want to retitle the thread so you get people reading it who can offer more help.

Try this at work. Open System Preferences/Network, make sure the WiFi is selected in the left column, then Advanced. Under the Wi-Fi tab, select your work network, then click on the "-" at the bottom of the window to delete it, then the "+" to add it back in and update the password. That action forces a re-connection as if it were a new network altogether.