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On this page we provide help for a number of common problems encountered with the OT. If you have any further questions or discover a new bug, please contact us via the ALMA Helpdesk.

Which version of Java am I running?

To run the OT, Java 6 or 7 must be installed. Check your java version on the command line by typing

> java -version

The output should read something like this:

java version "1.7.0_13"
Java(TM) SE Runtime Environment (build 1.7.0_13-b20)
Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)

An output like this (with the 1.7.x) means you have Java 7 installed. The results for Java 6 will be similar.

What do I do if I don't have Java 6 or 7 installed?

If you do not have an acceptable version of Java installed, go to Download and install Java Runtime Environment Version 7.0 - this is recommended, although this can only be installed on Macs if Lion version 10.7.3 or above is installed. If it isn't, Java 6 should be used instead. For LINUX users we also provide an OT installation complete with the appropriate version of Java (see the tarball installations page).

Is my Mac configured correctly?

On many Macs, although the correct version of Java is installed, this isn't set to the default. For older Macs, this can be solved by starting "Java Preferences" - this lives in the Utilities subdirectory of Applications, but can quickly be found using Spotlight. Clicking the General tab will  display the available Java versions which can then be rearranged into an order of precedence. On newer Macs, Java Preferences has been replaced by a Java Control Panel that is launched from System Preferences.

What do I do if I can't install Java 6 on my Mac?

Apple do not provide Java 6 for 32-bit Macs (Intel or PowerPC) unless you are running OS X 10.6 (Snow Leopard). This is clearly a significant issue, but fortunately there is a relatively simple solution in the form of an open source alternative called SoyLatte. SoyLatte does not appear to support Java Web Start, so it has to be used with the tarball version of the OT.

To get started with SoyLatte, first install it on your system and set the PATH and JAVA_HOME environment variables appropriately. You can check the SoyLatte java executable is found by the system by typing 'java -version', which should output something like 'Java(TM) SE Runtime Environment (build 1.6.0_03-p3-landonf_19_aug_2008_15_52-b00)'. Also, if you 'echo $JAVA_HOME' it should show the location of your SoyLatte installation. For more hints on installing SoyLatte see this page.

Another complication when using SoyLatte is that the web service libraries that come with it are outdated and must be replaced with a more recent version in order to be able to search for investigators in the ALMA user database. To get around this, you need to download the updated libraries from and unpack them with

java -jar JAXWS2.1.7-20090419.jar

You'll need to scroll through the license agreement and click accept for the unpack to proceed. Copy the unpacked libraries into the SoyLatte endorsed directory with

mkdir -p $JAVA_HOME/lib/endorsed
cp jaxws-ri/lib/*.jar $JAVA_HOME/lib/endorsed

That's it! You should now be able to install and run the OT.

I am a Linux user running the Iced Tea version of Java. What do I do?

We have found some issues using the "Open JDK" versions of Java, especially when using Web Start. We thus recommend using Oracle Java for the ALMA OT. If a non-Iced Tea variant of Java is available then, to install the Web Start version of the OT, your browser needs to be configured to use the "javaws" executable that is included with the Java distribution. Scisoft users can use /scisoft/bin/javaws.

  • Firefox: Clicking on the Web Start icon may bring up a dialogue asking you which application to use. This can be used to enter the non-Iced Tea executable. If the dialogue does not appear, the Applications tab of the Preferences menu can be used to do the same thing.
  • Konqueror: This is more complicated, but the procedure is documented here.

As a last resort, the tarball installation is available.

What do I do if I am experiencing problems with Java Web Start?

To test whether your Java Web Start works, go to Sun's Web Start Demo Page and try to run one of the demo applications. On Sun's pages you find troubleshooting documentation in case it doesn't work - simply (re)installing Java may be the easy solution.

I am getting a "Could not find a role web service at ..." error message when I start the OT!

This probably means that you are running patch version 21 of Java 6. Newer versions do not seem to have this problem so the solution is to upgrade to one of these.

The Web Start version does not start and complains about a "missing permission manifest"

If the Java installation is Version 7 Update 51 (or higher) then it is likely that this version of the OT does not conform to the new security protocols introduced in that version of Java (released in January 2014). This will be corrected in future versions of the OT, but for now, the best workaround is to add the Science Portal url (e.g. for European users) to the list of site exceptions that is editable from the Security tab of the Java Control Panel. If such a list is not available, it will instead be necessary to lower the Security Level to "Medium".

What do I do if startup of the OT fails?

If the startup fails, or the application freezes with the Splashscreen showing, please try these – ascendingly dramatic – options:

1. Delete the folder .almaot in your home directory, then retry.

2. Open the Cache Viewer (javaws -viewer), select the Observing Tool and press the "Remove Selected Application" button, then retry.

Providing feedback on problems

The OT provides a number of error dialogues and messages that should be reported together with the textual description when filing a Helpdesk ticket. An additional source of information is the "ot.log" files that are created in the .almaot file each time the OT is run.

Where do I find the .almaot file?

The .almaot folder is created in your home directory. On Linux and Mac this  should simply be /home/username/ . On Windows, this is usually "c:\documents and settings\yourname" or the localized equivalent in your language (e.g. "c:\dokumente und einstellungen\yourname"). You can also simply enter %USERPROFILE% in the address bar of the Windows Explorer, and it will take you to your home directory.

What do I do if the OT screen appears, but I permanently see dialog boxes saying "your current look-and-feel caused an error"?

First try switching to a different Look-And-Feel in ->Options->Appearance. If that doesn't help, you're probably running a buggy (or beta?) version of Java. Please update your Java installation.

What do I do if I see unformatted text or no content at all in the OT subwindows?

Your configuration files have probably been corrupted by a non-graceful shutdown of the OT. Delete the folder .almaot in your home directory, then retry.

Why am I experiencing disk space problems when running the Web Start version of the OT?

Java Web Start caches downloaded programs locally. For the ALMA Observing Tool, this will require around 70 MB of space on your hard disk. In case you run out of disk space or exceed your disk quota, you can change the location of the temporary internet files stored in the cache. To find these files, type

javaws -viewer

in an xterm and close the pop-up Cache Viewer. This will leave you with the Control Panel or Java Preferences Panel, where the temporary internet files are prominently displayed.