Is your hosting windows or linux? It’s working for me on 3 different hosting platforms (1and1, bluehost, godaddy) as well as my internal server.
Can you download the zip file to your local computer, unzip, and just FTP it to your server? Specifically:
Click the “download” link on the wordpress plugins page (http://ww.wp.xz.cn/support/plugin/adatosystems-friday-zmanim) and pull it down to somewhere on your computer
Go to that folder and double-click it.
Extract the files to somewhere on your computer. You only REALLY need the zmanfriday.php file
FTP to your webserver
Go to /wp-content/plugins
Create a new folder. I call it adatosystems-friday-zmanim but you are welcome to call it whatever you want.
Move INTO that folder
Uplaod the files to that folder
Go to the WordPress Admin panel, Plugins
Activate the plugin
Now go to Appearance, Widgets
You should see it in the list of widgets you can now use
Again, I’m not sure why the .zip file doesn’t work for you, but I’m more interested in helping you get the widget installed.
I’ve made some updates to the repository. Please try again. If this is working for you, please mark it as “resolved”. Thanks!