Saurik has released an update to Cydia Installer bringing support for iOS 8.3.
If you jailbroke your device using the TaiG 2.0 jailbreak utility. You should can update to Cydia Installer 1.1.17 through the application.
Here is what’s new:
Update Cydia to Support iOS 8.3
On iOS 8.3, Cydia would report that it “cannot identify your device” while trying to access your account. This was due to changes on iOS 8.3, and has been fixed.
Support file:/// Repository URLs
Recent versions of Cydia have rejected “local” repository URLs. This was due to an overly-limited filter on acceptable URLs. You can now again use local repositories.
If you’d like to download the latest version of Cydia, simply launch Cydia and you should be prompted to install the update upon refresh. This is not a fix for Cydia Substrate. The TaiG 2.1 jailbreak utility for iOS 8.3 has been leaked and it fixes Cydia Substrate, but this is not official release.