HEIF (High Efficiency Image File Format - sometimes with the extension .heic) is a new format used by many mobile devices to store pictures and video. The technology uses the h.265 codec for encoding of the files.
Support in macOS
FotoStation supports these formats natively in macOS, as they are the default formats used by iOS-based mobile devices.
Support in Windows
In Windows, support for this format can be enabled by obtaining HEIF and HEVC plugins based on the Windows Imaging Component framework (WIC) through e.g. the Microsoft Store. These are called "HEIF Image Extensions" and "HEVC Video Extensions" on the Microsoft Store, and both extensions are required to make the rendering work. Note that tey may be paid offerings.
Having obtained and installed the codecs in Windows, restart FotoStation to start using them.