Issue is referring to problems with Tinker's Construct mod. When crafting any piece of Manyullyn armour it has a tendency to craft with 1/1 durability and no statistics. Once broken, the armour breaks and can be once again repaired to 1 durability. Crafting pieces of armour doesn't always yield the same output. Crafting a slimelytra also has the same outcomes - however I have not found a way to craft it in survival. The only alternative is cheating one in from JEI - since even creative gives a 1/1 durability item.

This issue is outlined in the below post on the official Tinker's Construct github.
SlimeKnights/TinkersConstruct#4673

According to the author, the issue has been resolved in a newer updated version of the mod - however, the modpack still uses an older version. Would it be possible to update the official modpack to a revised 1.4 version, with other fixes and updates, in order to resolve this issue?