Hello,
I noticed that when I have an element in my workspace and it have a custom model (3D model), I cannot open element for change something. I hope that is only a bug in my Worskpace, but I give you my workspace. I suggest you to try with Dragonium Pickaxe, Dragonium Bow, Dragonium Hoe and Dragonium Sword ( you can also try with other things, because each ,element that I cann't open, has or had a custom model (3D). We can delete element and recreate it and after it work.
Goldorion
P-S : We cannot double clicks or click on buton "Edit selected mod element"
Issue comments
I have imported your mod in a development version of 1.8.3 and it worked so I think it should work.
A side note: some of the mod elements in MCreator 1.8.3 (blocks) will have build errors as we had to remove entity dependency from some block procedures (on block added for example) to make MCreator mods multiplayer compatible (https://mcreator.net/tracker/issue/40695). To fix this you will need to remake these procedures to not use the entity as a dependency or remove them from triggers.
I don't know why, but I cannot put my workpsace.