I mean that clipart have wrong data in database. English it's not my native language and I make mastake sometime sorry.
Some clipart was pretty old like my own clipart from 2006, there where probably some bug back then. Looking at my clipart from 2006 I saw that clipart that have date set to 00000000 was from the same time as my other clipart so I set all dates to 2006. there where other fileds that was blank or had bad entries I try to fix them all at once.
Maybe do you remember the year of the upload. old/very old/new/very new - estimation will be enough.
Now I see this is your profile http://openclipart.org/user-detail/c_schmitz on disk I se only one svg file and some f12.jpg. And your clipart is showing here http://openclipart.org/user-detail/c
Did you upload more then one clipart or only that envelope?