New index file won't open in Sky 8

[jope...@hotmail.co.uk]

Hi Collective Wisdom,

I need to start a new index but find that a previous index will not close; the message 'compacting database' appears ,and then after a while I get ' Sky not responding' and I end up closing it. Before all this I had downloaded DropBox as i have a large file to send soon. At one point  a message popped up in S8, ' Do you want to delete the (as-described previous) index from Dropbox?' so i said 'yes' to see if it would help, but no change. Also, bit confusing as I had not imported any indexes into DB (some still in One Drive). 

Any ideas/help welcomed!

Jo