Here are some suggestions on troubleshooting special characters and symbols in a PowerPoint presentation:
- Check to make sure the text is saved in Unicode UTF-8 format.
- Make sure the Font you are using supports special characters and symbols.
- Check to make sure you are using an updated version of Microsoft PowerPoint.
- Check the spelling of the text before inserting it into the Presentation.
- Try inserting the text/symbol from a different source.