I had not heard from him for an extraordinarily long time and was delighted to receive this:

I have been unsuccessful getting a viable response to a Linked-In related question. This includes having attempted multiple times to get help from Linked-In directly  through their help resource.

Simply stated, when I get messages or posts with video, the video ONLY plays if it’s based on YouTube. Many holiday greetings etc. came to me with smart device generated videos. I couldn’t make them play. They all had a Play icon, but that didn’t work. This includes primarily 1st level connections.

Yes, YouTube always plays well with LinkedIn. Just remember to set the thumbnail to one you want to appear on your LinkedIn message.

But that does not answer the real question of video formats that LinkedIn also plays well with.

My response to him (and you):

To answer your question, LinkedIn limits the types of video to be viewed on your LinkedIn Home Page to certain formats sent through its messaging function as attachments: https://www.linkedin.com/help/linkedin/answer/a548372.

I also received a number of holiday videos and for those I could not open on LinkedIn, I cc’d the URL (from those I knew and trusted!) and opened them on my browser. I do not recall any other issues. I hope the above helps.”

I hope it helps you too. Video on LinkedIn is a huge draw for increased attention and cements memory of you, but when it doesn’t open, well, that also has an attention element (like poof! they leave) and not the memory you want to create.

For now (until something else changes) I suggest you use only the  formats in the link I provided.

Any other questions? Happy to help solve LinkedIn mysteries (and there must be so many out there!)