Sophos AutoUpdate Status Window always "Downloading..." at 100%

Hello,

Recently, the Sophos icon started showing it is downloading in my Mac's menu bar. The download icon shows a litle animation with an arrow pointing down. It has not stopped for quite some time now. When I choose the "Show AutoUpdate Window" option, I get a window titled "Sophos AutoUpdate Status" and it shows a download status bar that is all the way at 100%.

I don't know if the file is being blocked, is stuck at some 99.9% download, or if there is something nafarious blocking the download. After checking the AutoUpdate preferences, nothing looks wrong (not that I know if it is right either). I did try setting it to use no proxy for an hour or so but that didn't seem to change anything.

I am using a MacBook Pro with Yosemite 10.10.4 and I do occassionally use various VPNs for work.

Do you have any idea how to fix this and/or prevent it from happening in the future? I am hoping restarting the computer regularly is not the answer.

Thanks.