After installing version 617.391, verify the build number:
The version you are looking for is a legacy version of Smart YouTube TV smart tv youtube 617 391 download latest version upd
The number 617.391 specifically refers to the Android TV package. Samsung and LG use different versioning (e.g., 2.34.05) but contain identical feature sets. For those TVs, simply check the Smart Hub or Content Store for the update dated within the last 7 days. After installing version 617
On your Smart TV, go to Settings > Security & Restrictions and toggle on "Install Unknown Apps" for your browser or file manager. After installing version 617.391
After an hour, he found it. A clean link on an archived server. A digital ghost. The file was small. YouTube_v617_391_legacy.apk .