When using Windows, you need to make sure that the architecture of installed LibreOffice matches the architecture of installed JRE. If your Windows is 64-bit, LibreOffice Download page by default offers you a 64-bit LibreOffice installer. It is designated as . If you have 32-bit operating system, you will be offered a 32-bit installer ( ). You may check the architecture of installed LibreOffice in menu ▸ , where the version string looks like "Version: 188.8.131.52 (x64)" for 64-bit version, and "Version: 184.108.40.206 (x86)" for 32-bit version.