In the directory where your orbitcoin-qt is located. Rename .orbitcoin to data if on Windows. Although you may just wait for the wallet to sync on its own.
To rename it? data.tar.xz
Tried, put this file in different folders, there is no result. Normal synchronization is in progress.
It is an xzipped tar archive. I've thought it's obvious from the extension. Use 7-Zip to extract on Windows.
What does the button mean, coin control, in the wallet?
It's the Coin Control. Enable it, restart the wallet and see it appear in the send panel.