I have error code NP-103418-7 what do I do to fix it

I am getting exactly the same thing on my PS5.  It will not let me play any of the PS4 games I have on my external hard drive, it just aborts out with this.  It will also not let me play any of the new games in the PS Plus Collection released for PS+ members with PS5s (same error).  If I delete the record of a game I've bought digitally in my collection, ie Far Cry 4, and then re-download the entire game, season pass and DLC to the PS5, it still does exactly the same. If i delete the record of a game I own on disk - ie The Last of Us remastered, and then re-install the game from disk to the PS5, it does exactly the same thing.

PS5 games that I have work perfectly. Just none of the PS4 ones.   My external drive works ok with the games on it when I plug it back into my PS4 Pro.

So much for backward compatability !!!

Seems all the NP errors refer to issues with the Playstation network.  I replaced the modem at this end for the internet, there are no fancy settings in it as far as port forwarding or anything like that.   Just frustrating that I can't play about 5TB of PS4 games that I have collected over the years.

Adysrc94.

Just as a followup to my previous message where I was getting same thing as you, I managed to get my PS4 games running on the PS5 properly without getting the error.  I can't pinpoint it exactly, but I think there was some sort of corruption of my PSN account setup on my PS5 when I initially set it up. I connected another external hard drive to the PS5 just in case it was an issue with my original one, and formatted it for use.

What I did do was start the PS5 in safe mode. Shut the PS5 down completely, then hold the on button until you get the second beep.  You will be prompted to plug a USB cable into the PS5 and connect the controller to it.  Press the PS button on the controller when prompted.  Once in safe mode you will get to a menu.  Chose option 6) Reset PS5 - it will take it back to its original out of the box state without doing a full firmware reinstall.   Set the PS5 up normally without the external drive plugged in.  Set up your PSN account, plug external drive in - in my case this new one was blank so I formatted it in the storage option.

Then try installing a PS4 game you have on disk and see if it installs on and runs.  Then try it with something you have as a paid digital download, test it to see how it goes.  I used Far Cry Primal (disk version I own) and Far Cry 4 (digital purchase) to test out the above, they both work.  Just means reinstalling them.  Will try and figure out how to get game saves across from the PS4 next (its late night here in Australia) - but some of these games I havent played for a long time so doesnt really bother me if I have to start them from scratch.  At least this way I dont see the NP-103418-7 error - your post here was the first one I've found online after searching for nearly a week.

Hope this helps at your end to solve your similar problem

Cheers from Queensland, Australia,

 JFK