Jetpack JSON API failed to activate bug solution

So, this is actually the part 2 of my problems concerning DigitalOcean WordPress 1-click-app and JetPack (about the first issue you can read here). If you read my first post you found out what I had to do in order to activate the Jetpack. All seemed fine and I could see the stats from WordPress installed on DigitalOcean droplet on my account and even some of the active things were working (like Photon or Contact Form).

But, when I wanted to turn on some of the Jetpack modules that I have previously turned off (or that were turned off by default) it didn’t work. For example I wanted to turn off and then turn back on JSON API at General settings tab. When I turned it off it looked like it “worked” (no error messages) but when I wanted to turn it back on I was getting following error message (and the slider won’t go to active position):

JSON API failed to activate. SyntaxError: Unexpected toket < in JSON at position 0


When trying to activate some other Jetpack module I would also get this error:

SyntaxError: JSON Parse error: Unrecognized token ‘<‘” error

I was also unable to disconnect the Jetpack using the account and this was only possible if I would disable Jetpack at plugins and re-enable it again. Then I would have to re-connect it with my WordPress account and it’s a loop but the results were the same. It didn’t work!

I have contacted Jetpack support but their help was similar to Microsoft support (restart the computer and try again), or in Jetpack case: disable all plugins and try reconnecting again. Since Jetpack support was unable to help me after we have exchanged couple of emails I have decided to dig deeper into this on my own. DigitalOcean community also wasn’t helpful since I found just one comment about someone having the same problem as I do but there were no reply or solution.

So I have opened Chrome debugger and have noticed that when I try to activate the JSON API it actually tries to make a POST call to url: /wp-json/jetpack/v4/module/json-api/activate:


and the result is 404 – the standard 404 page! Since there files on that path and WordPress installation doesn’t have wp-json folder at all I figured out that this is mod_rewrite path so I knew in what direction to focus my exploration. I’d like to mention here that this also happened on brand new, zero days blogs, no plugins installed, default theme: basically on out of the box WordPress installations. Also permalinks worked so mod_rewrite was working normally (or it appeared to be working normally), and that made the situation even more confusing.

Out of pure despair I tried re-enabling mod_rewrite and restarting apache:

sudo a2enmod rewrite
sudo service apache2 restart

And it FU*KIN WORKED!!! 

I have tired this on my other 5 or 6 sites hosted on DigitalOcean and it worked on all of them! I hope that some one from Jetpack or some geeks from DigitalOcean will see this post. I’d love to hear more about this issue. How is possible that mod_rewrite is working without being enabled on Apache or if it’s enabled why it doesn’t work for Jetpack plugin? I’m puzzled and I’d like some explanation.

Also I have one more bug that I don’t know how to solve. When I login to these WordPress admins I have this error on every (admin) page I load in my debugger:

Uncaught TypeError: Cannot read property ‘type’ of undefined(…)

This traces back to… as you can see in detail on this screenshot:


Update: 05th December 2016
Now Jetpack is works normally on my DigitalOcean droplets, but on some occasions while setting up the Jetpack options I saw this message: Warning! Multibyte support missing!


This means that multi-byte support php module was not installed. To get it installed simply install package php-mbstring using apt-get (or yum in case you’re using CentOS/RHEL Linux), restart Apache and you’re good to go!

sudo apt-get install php-mbstring
sudo service apache2 restart

PHP multibyte should now be installed and these messages should no longer appear.