1. Incorrect installation or problem: If you do not follow the correct steps when installing the blank sub-library, or there are problems during the installation, the installation may be unsuccessful or some errors may occur. At this time, you need to reinstall the blank library to ensure that you follow the correct steps.
2. Wrong path or lost file: If the installation path of the blank sub-library is wrong or the file is lost for some reason, it will not be found in SketchUp. At this time, it is necessary to search the correct path of the blank sub-library on the computer and set the correct path in SketchUp.