diff --git a/Modules/IGT/Testing/files.cmake b/Modules/IGT/Testing/files.cmake
index cc77978970..645738fc8f 100644
--- a/Modules/IGT/Testing/files.cmake
+++ b/Modules/IGT/Testing/files.cmake
@@ -1,65 +1,65 @@
 set(MODULE_TESTS
    # IMPORTANT: If you plan to deactivate / comment out a test please write a bug number to the commented out line of code.
    #
    #     Example: #mitkMyTest #this test is commented out because of bug 12345
    #
    # It is important that the bug is open and that the test will be activated again before the bug is closed. This assures that
    # no test is forgotten after it was commented out. If there is no bug for your current problem, please add a new one and
    # mark it as critical.
 
    ################## ON THE FENCE TESTS #################################################
    # none
 
    ################## DISABLED TESTS #####################################################
    # mitkNavigationToolStorageDeserializerTest.cpp # This test was disabled because of bug 17303.
    # mitkNavigationToolStorageSerializerAndDeserializerIntegrationTest.cpp # This test was disabled because of bug 17181.
    # mitkNavigationToolStorageSerializerTest.cpp # This test was disabled because of bug 18671
 
    ################# RUNNING TESTS #######################################################
    mitkCameraVisualizationTest.cpp
    mitkClaronInterfaceTest.cpp
    mitkClaronToolTest.cpp
    mitkClaronTrackingDeviceTest.cpp
    mitkInternalTrackingToolTest.cpp
    mitkNavigationDataDisplacementFilterTest.cpp
    mitkNavigationDataLandmarkTransformFilterTest.cpp
    mitkNavigationDataObjectVisualizationFilterTest.cpp
    mitkNavigationDataSetTest.cpp
    mitkNavigationDataTest.cpp
    mitkNavigationDataRecorderTest.cpp
    mitkNavigationDataReferenceTransformFilterTest.cpp
    mitkNavigationDataSequentialPlayerTest.cpp
    mitkNavigationDataSetReaderWriterXMLTest.cpp
    mitkNavigationDataSetReaderWriterCSVTest.cpp
    mitkNavigationDataSourceTest.cpp
    mitkNavigationDataToMessageFilterTest.cpp
    mitkNavigationDataToNavigationDataFilterTest.cpp
    mitkNavigationDataToPointSetFilterTest.cpp
    mitkNavigationDataToIGTLMessageFilterTest.cpp
    mitkNavigationDataTransformFilterTest.cpp
    mitkNDIPassiveToolTest.cpp
    mitkNDIProtocolTest.cpp
    mitkNDITrackingDeviceTest.cpp
    mitkTimeStampTest.cpp
    mitkTrackingVolumeGeneratorTest.cpp
    mitkTrackingDeviceTest.cpp
    mitkTrackingToolTest.cpp
    mitkVirtualTrackingDeviceTest.cpp
    # mitkNavigationDataPlayerTest.cpp # random fails see bug 16485.
    # We decided to won't fix because of complete restructuring via bug 15959.
    mitkTrackingDeviceSourceTest.cpp
    mitkTrackingDeviceSourceConfiguratorTest.cpp
    mitkNavigationDataEvaluationFilterTest.cpp
    mitkTrackingTypesTest.cpp
    # ------------------ Navigation Tool Management Tests -------------------
    mitkNavigationToolStorageTest.cpp
    mitkNavigationToolTest.cpp
-   mitkNavigationToolReaderAndWriterTest.cpp
+   # mitkNavigationToolReaderAndWriterTest.cpp # deactivated because of bug 18835
    # -----------------------------------------------------------------------
 )
 
 set(MODULE_CUSTOM_TESTS
   mitkNDIAuroraHardwareTest.cpp
   mitkNDIPolarisHardwareTest.cpp
   mitkClaronTrackingDeviceHardwareTest.cpp
 )