When I try to install TaskPaper from the HogBay website, I get this message:
“TaskPaper” can’t be opened because Apple cannot check it for malicious software. This software needs to be updated. Contact the developer for more information.
Thanks for letting me know, it looks like something changed and broke my code signing script for this release. I will try to get this fixed today.
In the meantime you can:
Right click on TaskPaper and choose “Open”. Depending on your macOS settings that will let you click through a warning and then open TaskPaper. And after you open it once it should open normally.
You can download the previous version of TaskPaper (3.9) from the releases page: TaskPaper – Plain text to-do lists for Mac
Sorry this took longer then I expected, but if you download from www.taskpaper.com the download is again correctly signed and notarized.