After several years of flawless performance by Keypass, yesterday it started opening websites totally unrelated to the target. I recently bought a Chromecast device and one of the changes I made on my desktop was to switch my default browser from IE 11 to Chrome; not a required change but I thought it would be easier to cast content under Chrome.
On a hunch, I reset my default browser to IE and Keepass resumed its normal operation. I hope this helps someone with a similar issue.
HP Laptop, Windows 8.1