I have no issues to install xposed. BUT: If you have xposed installed on 5.0.2 you have to uninstall it BEFORE Update to 5.1.1! Otherwise if you are using XperiaXposed you will end up with homescreen not starting (black screen) To do this:
1. Download xposed uninstaller zip and put it on SD Card.
2. Under 5.0.2 go to xposed installer and unload all modules and Reboot device
3. Boot to recovery and install xposed uninstaller.zip
4. Uninstall xposed installer
5. REBOOT (this is essential) and wait until all apps are optimized.
6. boot to recovery and install 5.1.1 firmware
7. Download latest xposed (xposed-v74-sdk22arm) and copy it to SDCard
8. Boot into recovery and install it.
9. Install XposedInstaller_3.0_alpha4.apk and you are done.