To open the Apple iPhone .heic photos, the Google .webp images or the AOMedia .avif files it's necessary to have the following WIC codecs installed:

Windows 10

.heic

Install both HEIF Image Extensions and HEVC Video Extensions from Device Manufacturer.
Note: if the Device Manufacturer version is not installing use HEVC Video Extensions or CopyTrans HEIC/HEIF.

.webp

Install Webp Image Extensions.

.avif

Install both HEIF Image Extensions and AV1 Video Extension.

Older Windows (including older Windows 10)

.heic

Install CopyTrans HEIC/HEIF.

.webp

Install Google WEBP.

.avif

No codec exists.

Attention: after the codec(s) installation please restart FreeVimager and then open your pictures.