Macintosh

If you run more than one client (e.g. a main and an alt), you're likely to have created more than one Library/Application Support preferences folder (two clients don't share a single prefs folder gracefully), and you're likely to be bypassing the launcher which stubbornly looks for the default prefs folder (which it can't find, since you've renamed it). This setup works well until the client requires an update... In which case you need to rename each of your prefs folder to the default ("Eve Online"), run the launcher, wait for the update to complete, quit, rename the prefs folder back, and update the Info.plist document within each client in turn to point to the actual game executable rather than the launcher (see https://forums.eveonline.com/default.aspx?g=posts&m=4613862#post4613862 for the original instructions).

With the new cadence of CCP releases, you're likely to have to do this more often than you'd like.

I've created a shell script to automate these steps: replace USER with your actual MacOS X user name, and make sure the paths to the apps are the same as your own. Save this to a file with a .sh extension and run it from the Terminal.

What the script does:

1. Renames your alt client prefs folder to the default
2. Runs the alt client launcher
3. Waits for you to press Enter to indicate that the launcher has finished downloading the update
4. Replaces the two strings contained in the Info.plist of your alt client to point it to your alt client executable again (they were overwritten in the update)
5. Renames your alt client prefs folder back to the alt name
6. Repeats the procedure for your main client (and you can copy-paste as many times as you have clients)

Script is available here. Hope it helps.