Salem

First I lost some animal glue that I had made and added to the sign inside my house so I went and bought more deer hoofs at the market place.
When I added the final 3 animal glue that I needed and was ready to build the cupboard I clicked the "Build" button and everything poofed.
I found 3 animal glue but nothing else in my inventory. >.>

So this is how it works.

When you add building material to an place(able) object without actually pressing the build button then the building materials you placed inside slowly decay over-time if left there for too long.

This was added a long time ago to prevent people for hoarding building materials via unfinished structures, for example: churches that can take 2000 stone, 1000 granite, etc. (lots of materials) that can be taken out whenever since they aren't actually built in yet. Even though stockbins have been added that alleviate the stocking problems of certain materials I believe that it is still okay that materials decay if not built into it.

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As an alternative question because this does still sound like a weird coincidence of some other mishap. Did the cupboard you were building in said house reside on a Pclaim or Tclaim? If not, then it could have decayed because of that reason alone regardless of building materials into it as all objects decay over-time without any claim covering it(Sign-posts for objects being built have rather low hitpoints and will decay very quickly this way as compared to other objects such as walls or houses that have much more hitpoints)

The cupboard was on a personal claim. I had to go buy more deer hoofs to make the animal glue to complete it.
Thanks for your reply.