I opened a video and got a notification that a new version was available and a link if I wanted to know more. Then I tried to close the video that was playing and couldn't. That was unusual. Then to the taskbar and said close (smplayer) window and it still wouldn't close. Finally in task manager I could close it. I don't recall getting notification on a new version before and I have had no problem closing a video window so that was strange. Then I followed the link to "Fosshub" where it complained about my adblocker and suggested I donate to them using Paypal. Then I downloaded the 64bit Windows version and when I clicked it to install Win10 Defender told me that it had stopped an unrecognized program trying to install. The descriptions of what has changed in vers 19.5.0 seemed realistic but I thought I would check here before going further with the install. Thanks.
ps After writing this I started a different video. Got the notification of a new version again. I watched the video for some minutes then when I clicked on it got only the error sound and couldn't access it anymore. Again I couldn't close it and had to go to task manager to do that.