Please try make a next steps:
1. Go to C:\Users\<user login>\AppData\Roaming\Stellarium directory
2. Open config.ini and set:
2a. base_font_name = TH Sarabun New
2b. base_font_file = THSarabunNew.ttf
3. Go to data directory (C:\Users\<user login>\AppData\Roaming\Stellarium\data or C:\Program Files\Stellarium\data)
4. Put THSarabunNew.ttf into here directory.
5. Run Stellarium and check fonts.
Please try make a next steps: AppData\ Roaming\ Stellarium directory AppData\ Roaming\ Stellarium\ data or C:\Program Files\Stellariu m\data)
1. Go to C:\Users\<user login>\
2. Open config.ini and set:
2a. base_font_name = TH Sarabun New
2b. base_font_file = THSarabunNew.ttf
3. Go to data directory (C:\Users\<user login>\
4. Put THSarabunNew.ttf into here directory.
5. Run Stellarium and check fonts.