Please post your logs using
pastebin.com (the contents of armorylog.txt AND dbLog.txt... or you can use "File -> Export Log File..." and post the contents of that file on pastebin), so we can help identify exactly what the issue is.
Having said that, the most likely problem is that you have Bitcoin Core setup to use a "custom" location for blocks, and Armory is not configured to look in that "custom" location, so it is looking in the "default" Bitcoin Core location and not finding anything.
Once you post your logs it'll be much easier to properly diagnose your issue.
