Small teambuilder issue
Select a champ in which you own multiple skins. In this case I own two varus skins and I have the 2nd one selected.
Then select a champ which you own at least one skin on, but has to have less skins in total than the position of the skin you selected..
I selected Kalista, which I own bloodmoon and she only has one skin, which is less than my varus skin position.
When I select kalista, client realizes I own skins on her and tries to do something resulting in Error(Invalid Skin). Most likely from the position of the last skin selected and no such skin existing in that position of the newly selected champ.
If you do not own skins nothing happens. Also after a short time a new error popups saying "We didn't hear back from the server. Please try again."
This isn't a big issue, but it does happen.