Try clearing your cache first (unplug PS4 at back of console for 30 secs).
If that doesn’t work, delete the game from your HD, back up your saves first. Download the game and apply the latest patch and hotfix.
If that doesn’t work, upgrade your internal hard drive.
If that doesn’t work, use MoD to destroy your PS4 and buy a PC or XBone X.
3 things I have found that make MoD not work properly. #1 is the internal memory and hardware of the PS4 is inadequate for the game, period. The issue is exaggerated when patches are applied on top of patches, and when hot fixes are applied on top of hot fixes. Also, the more projectiles being shot, the more loot that’s on the ground, the more memory and CPU is used. MoD tends to fail when players, enemies, projectiles and loot increase.
For example, a computer that controls a vehicles engine and power train, is sophisticated and processes information on the fly. Programmed in the ECU are tables that control various components, so when criteria A meets Criteria B the action placed is X. There could be dozens of tables, and more sophisticated machines could have into the hundreds.
Now, look at Borderlands and how many additives and multipliers there are. For every piece of gear. Tables of characters, skills, action skills, guardian ranks, weapon types, elemental damage, normal bullets, splash bullets, shields, artifacts, class mods, grenade mods, perks, modifiers, difficulty levels, maybe even down to each individual gun and their variations! Basically, there is a sh*t ton of tables and processing. As much as possible is stored into the internal memory of the PS4. The issue is more present in PS4’s because PC and Xbox have stronger hardware.
I can’t confirm that this is all fact. I’m basing this off my personal experience.
The #2 reason for MoD failure is from exploits and glitches. These glitches can be holes in the software/tables in the programming. This can cause confusion in the processing and internal memory. Another reason to reset your cache!
#3 is caused by error in the programming. Some of us have found certain artifacts to cause MoD failure, one specifically is a last stand loaded dice. There may be others.
What I have done to greatly improve Means of Destruction is replace the internal hard drive of my PS4 pro with a Samsung Evo 860. The difference is night and day, not only with MoD but the smoothness of gameplay, graphics, gameplay slowdown, blue screens, crashes, etc…
It might help to put your graphic settings to performance as well.