.. _troubleshooting:

Troubleshooting
===============

As a general rule, when you encounter an issue, always make sure that
you use the `most recent version
<http://www.orthanc-server.com/download.php>`__ of Orthanc.

Also make a search on the `Orthanc Users discussion group
<https://groups.google.com/forum/#!forum/orthanc-users>`__, and make a
search in the present Orthanc Book (there is a search field at the top
of this page). Your issue might indeed have already been discussed in
the past or in the FAQ.


Orthanc Explorer
----------------

* **I cannot login to Orthanc Explorer**: For security reasons, access
  to Orthanc from remote hosts is disabled by default. Only the
  localhost is allowed to access Orthanc. You have to set the
  ``RemoteAccessAllowed`` option in the :ref:`configuration file
  <configuration>` to ``true``. It is then strongly advised to set
  ``AuthenticationEnabled`` to ``true`` and to add a user to the
  ``RegisteredUsers`` option, also in the configuration file.


Performance issues
------------------

* **Orthanc Explorer is slow under Windows on the localhost**:

  - Favor ``127.0.0.1`` instead of ``localhost`` when specifying the
    network address of a server. Users have reported that this minor
    change `can massively improve performance
    <https://groups.google.com/d/msg/orthanc-users/tTe28zR0nGk/Lvs0STJLAgAJ>`__
    on Windows. Starting with Orthanc 1.0.1, the samples from the
    source distribution have been adapted in this way.

  - As an alternative, you can disable IPv6 support. This is a
    Windows-specific problem that is discussed `here
    <http://superuser.com/questions/43823/google-chrome-is-slow-to-localhost>`__
    and `here
    <http://stackoverflow.com/questions/1726585/firefox-and-chrome-slow-on-localhost-known-fix-doesnt-work-on-windows-7>`__.

* If you experience **slow DICOM transfers under Linux**, please read
  the `following bug report
  <https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=785400>`__. This
  issue does *not* affect all the versions of Linux. A
  patch to this issue is shipped with the Orthanc source code. In
  order to take advantage of this patch, you need to statically link
  Orthanc against DCMTK by using the ``-DUSE_SYSTEM_DCMTK=OFF`` flag
  `when invoking CMake
  <https://bitbucket.org/sjodogne/orthanc/src/default/LinuxCompilation.txt>`__.


Windows-specific issues
-----------------------

* Under Windows, Orthanc creates the "OrthancStorage" folder, and
  crashes with the error "**SQLite: Unable to open the database**":
  Your directory name is either too long, or it contains special
  characters. Please try and run Orthanc in a folder with a simple
  name such as ``C:\Orthanc``.