evidently the glyph with the code \x2212 is not available in the original TrueType font or it is not included in the font resource.
Are you sure the selected TrueType font does contain this glyph? It is not obvious. The designer of the font can decide whether and which glyphs do belong to it. If this is the problem, you will need to select another font or anothe character code for glyph existing within this TrueType font.
Another possibility: to save memory in the target system, Embedded Wizard imports (converts) only those font glyphs which you have explicitly specified in the attribute Ranges of the font resource. Per default, for every new added font resource, this attribute addresses glyphs in range 0x0020-0x00FF. Review this attribute and if necessary modify it to include the code \x2212. For example:
See also the section: Specify the text in our documentation.
Hope it solves your problems.