agouibo There seems to be some discrepencies between how the SpriteFont object measure its text between the C2 and C3 runtime.
My template use a temporary SpriteFont object to measure single lines of text and insert line breaks accordingly so they occurs between complete words only. However, even if this temporary object is set to have a width of 5000, the C3 runtime seems to execute the "TextWidth" expression still with the default width of the SpriteFont object. Everything breaks down and no line breaks get inserted.
A dirty workaround for this is to set the SpriteFont object's default width to 5000 or something, so the "TextWidth" expression works as it should.