Here's my log. Since you use screen watching according to the web page, maybe this has to do with the fact I have a 4k monitor?
01:29:51.120 [ main] INFO net.hearthstats.Main - **********************************************************************
01:29:51.123 [ main] INFO net.hearthstats.Main - Starting HearthStats.net Uploader 0.16.0 on WINDOWS
01:29:51.124 [ main] INFO net.hearthstats.Main - os.name=Windows 8.1
01:29:51.124 [ main] INFO net.hearthstats.Main - os.version=6.3
01:29:51.124 [ main] INFO net.hearthstats.Main - os.arch=x86
01:29:51.124 [ main] INFO net.hearthstats.Main - java.runtime.version=1.7.0_55-b14
01:29:51.124 [ main] INFO net.hearthstats.Main - java.class.path=C:\Users\John\Desktop\HearthStats.exe
01:29:51.125 [ main] INFO net.hearthstats.Main - user.language=en
01:29:51.125 [ main] INFO net.hearthstats.Main - **********************************************************************
01:29:51.717 [ main] INFO net.hearthstats.app - HearthStats.net Uploader v0.16.0-WINDOWS
01:29:51.718 [ main] INFO net.hearthstats.app - 1 - Set your deck slots on the "Decks" tab
01:29:51.718 [ main] INFO net.hearthstats.app - 2 - Run Hearthstone in <strong>WINDOWED</strong> mode
01:29:51.718 [ main] INFO net.hearthstats.app - 3 - Look for event notifications in this log and bottom right of screen
01:29:51.719 [ main] INFO net.hearthstats.app - 4 - <a href="http://goo.gl/lMbdzg">Submit feedback here</a> (please copy and paste your log file in C:\Users\John\Desktop\log.txt)
01:29:51.720 [ main] INFO net.hearthstats.app - Checking for updates ...
01:29:51.720 [ main] INFO net.hearthstats.app - Latest version available: 0.16.0
01:29:51.720 [ main] WARN net.hearthstats.app - Userkey yet not entered
01:30:31.622 [ main] WARN net.hearthstats.app - Userkey yet not entered
01:30:44.210 [ main] INFO net.hearthstats.app - Userkey stored
01:30:44.211 [ main] INFO net.hearthstats.app - Waiting for Hearthstone (in windowed mode) ...
01:31:22.286 [thread-5] INFO net.hearthstats.app - Hearthstone window found with process name Hearthstone.exe
01:31:22.519 [thread-1] INFO net.hearthstats.app - Hearthstone running in fullscreen
02:02:57.324 [thread-1] INFO net.hearthstats.app - Hearthstone window with process name Hearthstone.exe closed
02:03:06.621 [thread-4] INFO net.hearthstats.app - Hearthstone window found with process name Hearthstone.exe
02:17:26.368 [thread-3] INFO net.hearthstats.app - Hearthstone window with process name Hearthstone.exe closed
Here's my log. Since you use screen watching according to the web page, maybe this has to do with the fact I have a 4k monitor?