You need at least Camera Raw 16.3 or 16.4, so installing Camera Raw 16.5 should work for opening the
Fujifilm X-T50 raf files.
https://helpx.adobe.com/camera-raw/kb/camera-raw-plug-supported-cameras.html
Have a look at the instructions for updating the Camera Raw plugin for Photoshop Elements here:
https://community.adobe.com/t5/photoshop-elements-discussions/manually-install-adobe-camera-raw-acr-nicer-to-look-at/td-p/14539971
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