In recent weeks, some players of Monster Hunter Wilds have encountered various issues related to the game’s crafting system. A discussion came up on Reddit, where a user was confused because they could not craft a specific weapon despite meeting the material requirements:
How to Craft Your Weapons
While you can, in theory, craft all the weapons you want, there are a few things you need to know. Some weapons not only need the materials but also the previous weapon to be crafted on the Tree.
When you go to Gemma and under the weapon crafting tab, you will see the hammer icon on your weapons. This icon indicates direct crafting availability, but depending on the color of the Hammer, you may need to craft other weapons first.
The Blue Hammer means you can directly Forge the weapon, and the Purple Hammer indicates that you can craft it, but require forging the previous weapons in the same tree first.
For example, in the Reddit post example, the person wants the Lala Barina Weapon. For this, they need to forge the First Bone Tree weapon to then access the Lala Barina Tree:

You can switch to the Forge list next to the weapon tree. This way, the game will only list all the weapons you can forge. The Upgrade list on the other hand will show you only the weapons you already forged, and that you can upgrade.
Once you forge the first weapon, you have to upgrade it until you reach the weapon you want. This means sometimes having to go back to farm some Low Ranks Hunts. However, those should be rather fast to complete.