I experienced a similar error. The trouble is that loading-page.html has a incorrect address localhost:8080 for jupyter notebook. The connection to Jupyter notebook is localhost:8888/ not localhost:8080 now.
I assume your started Mac Application of Sagemath by Double click, Dock or LaunchPad. Please verify your opening window has heading: "The SageNB server or Jupyter is currently starting. Please wait..." There are buttons "SageNB interface" and "Jupyter". Both of them link to localhost:8080 mistakenly. Please try opening localhost:8888 form your browser. Or if you are familiar with Terminal.app, please use the command " open http://localhost:8888 ". If this opens a Jupyter notebook or its login page, my workaround should be good for you. My workaround is to edit loading-page.html by a text editor. You should login MacOS with the same account as the time of your installation of SageMath. If you put SageMath-9.0.app in /Applications folder, you can locate the loading-page.html by the following pathname. /Applications/SageMath-9.0.app/Contents/Resources/loading-page.html If the version is different change "9.0" with the version of your SageMath application. (Form the Finder, the filename might appear SageMath-9.0 but from the Terminal, we have to write SageMath-9.0.app with the extension .app.) Opening this file from the Finder needs a technique of typing the path /Applications/.../Resources/ in the Finder's menu of "Go". But it is simpler to use /Applications/Utilities/Terminal.app and open the pathname /Applications/.../loading-page.html by your preferred text editor. Once opened loading-page.html, search for the string 8080. The second hit is in the following patter. <a href="http://localhost:8080/";>Jupyter</a> Change this occurrence of 8080 to 8888. Please tell me if it succeeds. I am planning to tell the developers many many improvements like this. If some developer is reading my comment, please arrange you I can report bugs and improvements. 2020年2月23日日曜日 4時09分44秒 UTC+9 James Traynor: > > I receive this response when I try to open notebook > > > safari cannot connect to local host 8080 > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/881a9307-305d-48e8-af3c-b0e19d77456f%40googlegroups.com.
