Missing Arc de Triomphe

Please help my Arc de Triomphe is missing, it was in the process of building but disappear. I can't find it anywhere look in storage, building etc. I even store everything in storage to leave my garden empty to see if it might have hidden underneath something but nothing help!!!!! Can I still go on with the game or am I stuck forever? Any help would be great. I have turn off my phone many time, deleted and installed many times as well.

Mine is now missing at I don't know where it went. It was there yesterday and today it disappeared overnight.