Q: iTunes 12.3.1.23 video playback not working

so how did you do this?

My issues started on all three machines when I downloaded El Capt a few days ago

No everything will remain the same, I only had to update Safari back to 9.0.2

That`s a different problem. For my use OS X 10.11.2 El Capitan is just a bad joke it breaks several applications rendering my Mac`s useless. Apple seems incapable of releasing an OS upgrade that is fully tested on their own hardware and their own software. The only real solution is to revert the systems back to Yosemite. For the first time in well over a decade I find myself looking at Windows based systems...

Apple could care less as long as they are selling product, hence why the quality of OS X has significantly degraded over recent years. In all honesty the recent OS X updates are more about "eye candy" than productivity, coupled with a diminishment in readability due to poor choice of fonts and a reduction of contrast across the OS. In many respects I don't get what Apple are striving to achieve, I do know I don't like the direction it`s going in...

Apple has always served the consumer, and in the "lean' times Apple rapidly learnt to gain support of a specific technical minority user base. Apple then provided hardware & software that met the users need. Spin on iPhone, iPad, IOS etc. The tiles have flipped Apple no longer needs you. This now results in ever more base consumer centric hardware & software and who can blame Apple as this is a function of profitability.

OS X is slowly becoming little more than a gateway to the internet, a vehicle for social media, with Apple treating the OS as mobile, with updates that are lacking quality; never finished, never complete..

It is with deep regret that I find myself looking at alternatives, purely due to Apple`s greed strategy...

I have the same issue with the latest security update and running 10.10.5.  My other MacBook that I didn't run the update plays iTunes movies fine.

I spent an hour on the phone with Apple Tech support level 2 and sent them captured files from the problem.

I said, I have friends with the same problem and this is not an isolated issue.  Then I checked here and see everyone has the problem

Funny, the tech support guy seemed unaware! Ha!

Followup: Fix worked briefly then same error came back.

We'll have to wait on a fix from Apple.

update to my situation:

since applying the latest security update 2015-005 none of the purchased video content in my iTunes library will play Over 50 tv series & 150 movies. I just get a black screen and no volume. My own movies / tv shows in iTunes library all play no problem, which eliminates hardware as do hardware tests completed.

Some content will play the intial intro providing there is connection to the Apple store, if there is no access then content refuses to play at all and will not play even when connectivity to Apple store is resumed.

I'm waiting for response from Apple Support.

Me too. Same issue, symptoms, OS and iTunes versions as the OP.

(not the most helpful response but nothing more to add really)

Guess we just wait for the time Apple deem it important enough to fix which will be round about the time they realise their movie sales are down for some strange reason.

As stated, if you download and run the 10.10.5 full OS X installer from the Apple Mac store you will be able to watch your paid iTunes video content as before. Apple may fix this in a matter of days or months. This is due to Apple not fully testing the latest security update, as they are only apparently concerned with El Capitan albeit another broken mess.

Since I ran the full OS X installer I have had no issue, inclusive of several cold starts, iTunes now plays as expected, all paid video content plays as it should.

iTunes 12.3.2 is out

Updating to 12.3.2 didn't make any difference for me. I'm doing a full time machine restore. What a complete waste of time and energy

I had the same problem and reinstalled the OS, using this link for reference... How to reinstall OS X on your Mac - Apple Support

And now I can view my videos on iTunes and Quicktime. But I won't be installing any new updates for a while!!

You only need to re-apply the OS X full installer and all should be good. I have done this and iTunes pays paid video content without issue, have just upped one Mac to late iTunes and still plays