To do this Tools -> Options -> Language Settings -> Writing Aids -> Uncheck all the other dictionaries in the "Available Language Modules" list and uncheck all except "standard" and "IgnoreAllList" in the "User Defined Dictionaries" list. In the latest versions of LibreOffice this step is no longer needed If after installing the spell checker it does not work then you need disable all the other spell checkers used in LibreOffice/Open Office. Tools -> Option -> LibreOffice or -> View -> uncheck the "use system font for user interface" check box. If that doesn't work try replacing "Segoe UI" with "Khmer SBBIC System" and it should work.
Please note: Not all of the Desktop fonts will be in non-desktop editions of Windows 10 such as Xbox, HoloLens, Surface Hub, etc. Below you will also find list of fonts in each of the Feature On Demand (FOD) packages. Tools -> Options -> LibreOffice or -> Fonts -> select apply replacement table -> In the "Font" drop down list type "Andale Sans UI" -> Select a desired Khmer Unicode font such as "Khmer SBBIC System" from the "Replace With" drop down list -> conform by clicking on the green correct mark -> When the new entry is added to the table below select "Always" check box. The following is a list of desktop font sets that are present in the most updated version (2004, May 2020 release) of Windows 10. Thank you to all the volunteers who made this possible! TO USE THE HYPHENATION DICTIONARY please read the instructions at: To display the suggestions correctly you have to change the display font of to a font that supports Khmer Unicode. In this release we added more Khmer proper names as well as additional number and date combinations. Also, now the ៗ character will no longer cause words to be misspelled. We also included some better coding to make the checker better at giving you a correct spelling for a misspelled word. No longer will Khmer numbers be viewed as misspelled words. Allows for Khmer numbers as well as the inclusion of ទី before numbers. Based on the word-lists of KhmerOS and SBBIC. An extension for LibreOffice to include a Khmer spelling checker.