"This file type isn't supported here"

Each tool accepts specific formats: video tools take MP4, MOV, WebM and MKV; image tools take JPG, PNG, WebP, AVIF, HEIC and GIF; the audio converter takes MP3, WAV, M4A, OGG and FLAC, or a video; the PDF tool takes PDF files.

What to try

Check that the file opens normally on your device. If it's an unusual format, export or save it again as a common one, such as MP4 for video or JPG for photos. Files with a wrong extension, for example a video renamed to .jpg, can also cause this.