Note that the OT Web Start is not supported anymore starting from Cycle 8
OT Web Start does not work :
After you click the Web Start icon, if the OT is still "loading resources" and does not proceed, you might want to save the OT by "download linked file as". Then go to the directory where you put ObservingTool.jnlp and run the OT manually by launching Java Web Start application from a command prompt by typing "javaws ObservingTool.jnlp".
If this does not work, you might want to delete $HOME/.almaot directory and restart OT as described in the troubleshooting page.
How to run the OT in windows 10?:
Try downloading the Windows Offline (64-bit) version of Java from here: https://java.com/en/download/manual.jsp and make sure your path points to this version of Java. Then click the Web Start icon.
If this does not work, you can also launch Java Web Start application manually. Detail instructions of how to do this depends on Windows. You can find useful documents in the internet including this link.