By launching H-Encore to hack your PS Vita, users will eventually experience a trophy warning whenever they try to open up a game. This guide will show you how to remove this warning by altering H-Encore through VitaShell.
VitaShell: GitHub Link
Step 1: Enable Unsafe Homebrews.
Go to Setting/HENkaku Settings and make sure Enable Unsafe Homebrews is checked.
Step 2: Launch VitaShell.
Step 3: Copy System.dat and remove PCSG90096.
Exit out of VitaShell and go launch H-Encore. The game Bitter Smile will pop up.
Step 5: Close H-Encore/Bitter Smile.
When you see this screen, close out of the demo, go back to the home screen, and launch VitaShell.
Step 6: In VitaShell Move System.dat Back.
Back in VitaShell, a new PCSG90096 folder will appear at ux0:user/00/savedata. Highlight system.dat, press Triangle and select Copy. Press X on PCSG90096, go to “..” and press Triangle and select Paste. Press O to go back to ux0:user/00/savedata, highlight system.dat, press Triangle, and select Delete.
Now whenever you open a game or app you will no longer get a pop up warning you about not being able to earn trophies.
Note: If you are using games or other apps with saved data from another PSN account you will also get the trophy warning and that is a different issue. Please see my guide here (https://psvitamod.com/saves) to remove that trophy warning.