If you are experiencing difficulties with network communications between two computers running Isadora, or between Isadora and another program, these troubleshooting tips may solve the problem.

You should quit and restart Isadora each time you try one of the steps below. Immediately after you start up Isadora, choose open the Isadora Preferences and see if there valid IP address at the bottom of the Isadora Preferences dialog. (Something like is valid; is  invalid.)

Ensure your firewall allows connections between Isadora and the rest of the network.

  1. Check that your computer itself has a valid IP address. On macOS you can simply look in the Network pane of the System Preferences. On Windows you can follow these instructions. If you don't show a valid IP address here, then there is something wrong with your computer's network setup.
  2. If you are attempting to use the Net Broadcaster, it is essential that you have a router that supports multicasting. Most routers support this feature, but an Internet switch or hub will not. (If you don't know the difference between a router and a switch/hub, read this.)
  3. Follow these instructions for macOS or Windows to ensure Isadora is not blocked by the Firewall
  4. If that doesn't solve the problem, on macOS you might need to go to System Preferences > Security > General and ensure that your computer will run programs from "Mac App Store and Identified Developers"
  5. If that still doesn't solve the problem, on macOS you can try changing your security settings to allow applications from "anywhere." Here's a procedure that explains how to do this in macOS 10.12 (Sierra) and later. (You can change the settings back back after you've tried this by using "sudo spctl --master-enable" instead of "sudo spctl --master-disable".)

If none of those steps work, tell us about it on the forum or open a ticket and we'll give you further assistance.