I have an asset without a status or an asset with errors in status column that cannot be cleared

If in your Library you have an asset that has no status and when you right click on it and choose option "Sync asset" nothing happens, please delete such an asset and re-import it (your asset got corrupted and is not available in Reacts). 

 

 If in your Library you have an asset  with errors in status column, right click on the asset, choose option "Clear errors" and try to sync the asset again. If it doesn't work, you asset got corrupted and need to be deleted and re-imported again.