FAQ

1. When I try to open the OT, I get a pop-up on my Mac telling me that it is from an unidentified programmer. I cannot continue to open the program. What should I do?This is a security measure that prevents viruses, etc. from running on your Mac by only allowing users to open apps from the App Store and/or “identified and trusted developers”. The workaround is to Control+Click or Right Click on the OT icon and select “Open” in the menu. Another pop-up will appear warning you that the OT is from a third-party developer. You can select Open and the OT will open correctly.
2. When I try to open the OT on my Mac, I get a Java Networking Error
   
   1. Resolution Step 1:
      The OT currently uses Java version 1.7, which has a known unresolved network issue on Mac OS. If your computer’s HostName as returned by the “scutil” command does not have a domain name, you will likely encounter this problem. For example:

      $ scutil --get HostName
      myhostname

      The symptoms are slow start times for the application and network connection problems in general. To work around the issue, one solution is to add a “.local” domain name. DO NOT CHANGE YOUR HOSTNAME as this could break your ability to login. Just add “.local” to your existing HostName. This can be done with scutil:

      $ sudo scutil --set HostName myhostname.local
      

      This will prompt you for your password, which must have sudo privileges.

   2. Resolution Step 2:
      If this does not work, check to see that your HostName and LocalHostName match.

      $ scutil --get HostName
      myhostname.local
      
      $ scutil --get LocalHostName
      notsamehostname

      if they do not, the safest thing to do is change the LocalHostName to the root of the Hostname

      $ sudo scutil --set LocalHostName myhostname

      Then check the names again:

      $ scutil --get HostName
      myhostname.local
      
      $ scutil --get LocalHostName
      myhostname

   3. Resolution Step 3:
      The only time you should change your HostName rather than simply append it with “.local” or change the LocalHostName is if the root of LocalHostName does not match the root of the HostName, because the Hostname is not set:

      $ scutil --get HostName
      not set
      
      $ scutil --get LocalHostName
      myhostname
      
      

      If you have no HostName (i.e.”not set”) than you will be required to change the root of your Hostname to the LocalHostName using the set command. You can do this and append “.local” at the same time.
      You may need to restart your system for these changes to be applied and visible to the OT.

3. When I try to install the OT on a Windows computer, I get a pop-up telling me that ‘Windows protected your PC’. How do I continue to install the OT?
   
   This is a security measure that prevents viruses, etc. from running on your computer by only allowing users to open apps from “identified and trusted developers”. The workaround is to click on ‘More info’. Another pop-up will appear (see below) warning you that ‘Windows SmartScreen prevented an unrecognized app from starting’. You can select Run anyway and the OT install will continue.
4. Image Servers list in the Position Editor does not match the image below:
   This issue is related to the JSky library used in the Position Editor and is beyond our control. Under some circumstances the catalog list used by the OT will default to an older configuration on the users’s computer. This will prevent the user from accessing the updated Image Server and Object Catalog lists in the OT.
   1. Resolution Step 1:
      Close your OT. Identify the location of the AstroCat.xml file on your computer. The likely locations for the platforms supported by the OT are given below.
      Windows: C:\Users\[username]\.jsky\AstroCat.xml
      Mac: /Users/[username]/.jsky/AstroCat.xml
      Linux: /home/[username]/.jsky/AstroCat.xml
   2. Resolution Step 2:
      Make a backup copy of AstroCat.xml in a safe location and delete the original file.
   3. Resolution Step 3:
      Open your OT and confirm that the Image servers list in the Position Editor now matches the image above. If it does not, please contact the Q-Dev team at queue_dev@lbto.org
5. Guide star selection results in a NullPointer Exception.

   This issue can arise when the OT is used for the first time on a computer. The very first usage of the GS Selection function has, by default, an empty entry for the Guide Star Type. When a query is attempted without selecting a Guide Star Type from the drop-down menu the OT will return an “inner radius is >= outer radius” error and all subsequent queries will result in a java.lang.NullPointerException.
   Solution: Close the OT and open it again to clear out the error. Once you have performed any guide star query with a properly selected Guide Star Type the drop-down menu should always have a valid pre-selected value.

6. OT appears to get stuck when a program is loaded or a new program is created.
   
   We had instances where the OT seems to get stuck when a program is loaded. The most likely cause of this is that the window opened outside the visible area of your display.
   Solution: Close the OT and delete the jsky.properties file from the hidden “.jsky” folder in your home directory. This will reset the display setting for the OT. Now the windows should open up again in the usual manner.