I have an iMac running High Sierra 10.13.6. I wanted to download the Tomahawk music player from the developer site at www.tomahawk-player.org. Safari tells me the connection is not private. It appears their certificate expired 99 days ago. This seems like a long time for that to go on without the owners of the website upgrading their certificate. I just want to know if I should ignore this warning. I'm very hesitant to go there.
According to sources that project has been "essentially abandoned" (nobody is working on it)
So, even if you download it, you are on your own with any problems that might occur.
As for accessing websites with expired certificate, you have been warned not to proceed, but you can at your own risk, witch could be major or minimal.
If you wish to proceed you can download the player from here
Just tried that and it Opens fine on HighSierra