The latest bug restarts the UI whenever you attempt to remove an installed app, thus preventing the app from getting wiped clean. This obviously could make things difficult for those looking to load up their Xperia Z Ultra GPe with apps, media and other content. Without being able to delete the ones that you don't need anymore, you soon could be bumping up against storage limits. The device has 16GB of native storage, of which 11GB is available to the user. And there is a 64GB capacity microSD slot, so you might be able to install quite a large number of apps and content before having a problem.
Hopefully Sony is working on a bug fix for the phone. In the meantime, you can see the bug in action by clicking on the video below.
source: +JRRaphael via AndroidCentral