Unable to convert to a compatible TrueType curve.

When I use bones to create variable fonts, it always shows “The character shapes are incompatible; cannot convert to compatible TrueType curves”, but when I click on the characters, it shows no error. Currently, the only solution is to expand the outline and align each point. However, compared to drawing the outline from the start, the expanded outline is too complex, especially for characters with many strokes, making it difficult to align two masters. How can this be solved?

However, no errors are shown in the glyph shapes. Only when exporting, the errors will be displayed. The TTF file cannot be exported.

That is a know issue with the rounded strokes. This will be fixed in a future version.