Energy that you've either earned, bought from say the Clan Shop/Tag Bazaar (that automatically goes to your energy total) or opened up from refills doesn't expire.
Those refills/unopened energy in your mailbox does expire eventually, but once opened it doesn't disappear.
The first thing I would do is make sure you're on the right account, if you have more than one.
i'm in right account .. it's not until mailbox at all , it was sitting in energy position like 124/124
yesterday it was 500/124 and now it's gone i know i did had it automatically on multi button but not up to zero it should be half of it when i woke up it was gone and impossible
bug ?
It honestly sounds like you just ran the energy down with multis then.
you can contact support through an in game ticket or here: https://plarium.com/en/support/ if you believe your energy to be incorrectly missing.