Got an info from ZOs about the error messages with "insecure code":
Code:
It's because the security of the handlers comes from the security of the function plus the security level when they are set (this second part is new). So when an addon tells the inventory to build a bunch of inventory slots, all those handlers are insecure and cannot call private functions. The next patch will change that so those handlers will be secure which will make these errors go away.
The explanation more in detail was finished with this information:
Code:
Things that change the bag that is shown by calling UpdateList on the inventory for example.
If you open the inventory first then the stock UI will make all the slots securely. Then when the addon does it they'll already be there to use.
So this is why opening the inv first made the errors stop for some time.
As the addons, and especially filter addons using LibFilters, use an update function to show/update the inventory rows this should relate to all of the addons like AdvancedFilters, FCOItemSaver, Inventory Grid List and others which add marker icons to the inventory rows (maybe even Craftstore or Alphagear).
I hope this will fix all the cannot pickup/deposit stuff as well or we need to see further after that patch then.