You want to consider submitting a ticket for your bug report of unable to attack while equipped with weapons wielded as this section is for suggestions and feedback.
Limited weapon slot
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Each weapon or tool uses a fixed slot. Larger equipment such as bows, shovels, 2-handed maces, etc take the only rear-slot (on your back) thus are visible on your back when equipped. Anytime you equip something and it's visually on your back covering your head/neck down to your waist, think of that rear-slot used and nothing else can be equipped there unless swapped from inventory.
Chest items - 6 max
Back items - 4 max
Rear items - 1 max
Lower Rear items - 2 max
There may be others but that's best I can cover for now based on what I have unlocked or crafted.
The weapon limitation issue you're experiencing has nothing to do with ranged vs melee. It's just assigned slot limits.
In the game there is currently an indicator on the hud when you place your mouse over items which tells you which slot it uses and how many of those slots are currently in use.
Unable to attack issue
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Is this on the official servers? (pve/pvp/etc). Are you using a keyboard and a mouse?
If you can record a video replicating the issue, it may help others assist you (whereever you post).
Additionally, you can try to include a brief capture of your settings (game and/or server whichever applicable)
Best of luck.
Suggestions To Devs+Web designer
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Ingame - I don't recall seeing it in the tutorials, but highlighting the slot limits for new players may help.
Website - Adding the weapon and tool slot information for quick reference may be useful as well down the line.