@Chrisssj2, after you have applied the app.db modifications you mentioned in the OP, are you then trying to just open the Near app normally via the LiveArea? If you are, then error C1-2758-2 will be a perfectly normal thing.
Don't forget that the reason behind swapping the Near eboot with the Manual eboot, and adding an extra URI call to the table, is to open the game's instruction manual in the swapped "Near app" via the said URI call in the
internet browser, and not just by going straight to the app via LiveArea.
For example, I want to decrypt Minecraft installed on my memory card.
I would just simply go to the internet browser, type in "ux0:app/PCSB00560" (without quotes)(PCSB00560 is MC's Title ID; replace that with your game on the memory card) and afterwards, the "Near app" should open and instead display the game's manual.
You can then simply minimize Near and manage your decrypted game from there on. (Assuming you copied the MolecularShell installation over to ux0:patch/TitleIDOfYourGame).