Thank you for looking into this.
I have checked the File with Excel 2013 15.0.5059.1000 32Bit and Excel 2016 16.0.10325.20082 32Bit, both Result in the shown image above.
We have successfully tested it on three different Workstations.
I also tested how the file looks if I save it in Excel as pdf, then bold and Italiv are set Correct in the header.
I have created a new File, same Styles, different Font(arial):
TextExcel3, tested on two different workstations:
TextExcel3.zip (6.6 KB)
If this too fails, can you try to set the ‘Bold Text’ to Bold and then go into preview in Excel. Then it should be shown as Bold. Maybe you can reproduce the Issue that way.
Should it work with that File, yould you provide it to us?
Is it possible that this Issue is related to the language of the Computer or in Excel?
Thank you for your Help so far.
EDIT: I may have found the Issue: Language.
In German (my native Language), the Header looks like this, when i open it in Open XML SDK:
&L&"Arial,Standard"Simple Text&"Arial,Kursiv"Italic Text&C&"Arial,Fett"Bold Text&“Arial,Standard”&UUnderline Text
The two words (Kursiv, Fett) mean (Italic, Bold) in English. This would also explain why the Excel is broken on your PC’s.
Can you reproduce/fix this in Aspose?