Check your C:\Users\%user\AppData\Local\DayZ
& Clean it up once in a while ;)

If players are getting crash.log outputs:

NULL pointer to instance
Class: 'CraftingBookUI'
Function: 'Update'

OR

NULL pointer to instance
Class: 'Hologram'
Function: 'EvaluateCollision'

These workarounds are maybe not ideal but work good enough for me:

To get around the 'CraftingBookUI', which seems to be caused by "reading" the BBP Blueprint object in your hands or on the workbench, you can spawn the kits as loot or sell them at a trader instead of letting players craft them. Turn off the blueprint spawns altogether. Don't spawn any workbench kits, and don't sell these objects either. That way players must find or buy the building kits, and can't build the workbench or craft any kits. You can spawn them in creative ways, maybe in construction buildings, around lumber piles, or in basebuilding airdrops. If you are using BBP Item Pack you will have to turn off that blueprint spawn as well, and spawn the craftable items for players if you want.

For the 'Hologram' issue, which seems to also cause players to have difficulty placing objects on BBP structures, you can turn on disableIsCollidingBBoxCheck AND disableHeightPlacementCheck in your cfggameplay.json file.

Make sure that the cfggameplay.json file is being read, in your serverdz.cfg file you need to include the line

enableCfgGameplayFile = 1;

This workaround should allow you to place objects normally on your BBP structures and prevent the .log file spam.

I hope this helps people!