Some users may meet with the problem that the 3uTools or other apps can’t be opened on iOS9, and it has one and only option “Cancel”. So how to solve this such kind of problems? You just need to open the “Settings” of your iDevice →click the button “General”→find and click the option “Description files” (Device Management)→click on the button “Trust”.
If you can’t open the apps downloaded from the 3uTools, please try the following steps.
Step 1: When you open the 3uTools, the system will give a reminder. Then you have to remember the English part of this reminder.
Step 2: Please open the “Settings” of your iDevice→click on the button “General”→choose the option “Description Files”.
Step 3: then you need to find and click the previous description file.
Step 4: Please click on the blue words→ click the button “Trust”, and then you can return to the desktop and open the 3uTools again.