I imported a font for edit, chose the script to rotate by 180 degrees, but after installation, latin characters are shown correctly (inverted), however greek characters are shown as rectangles. Why is that?
Because you’re using the unregistered trial version of FontCreator.
Read the FAQ at the top of the support forum
Latin characters are displayed correctly. Only greek rectangles are rectangles.
That is expected. The Trial version only exports a limited set of Latin Characters.
Please register the program if you want to use it to create fonts. No development can happen if no one buys the program. It is not like a free browser that gets revenue from Google who pay to get access to your browsing habits for the benefit of their advertisers.