Home automatically redirects to /undefined

After updating to WP 4.2.3 the home page automatically redirects to /undefined.
I've tried reinstalling WP (clean), I've tried deleting the home page and recreating it, although Themia uses its own homepage. I've checked all the permissions on the server. I deleted all plugins (one by one) and reinstalled them after no improvement. I'm not using a redirection plugin. I updated Themia to the latest version.

When I change the theme, I don't have a problem. Suggestions are highly appreciated at this point.
Site: www.glmhydro.com

 

Hello,

Please send me your dashboard details. I will forward it to our technical support team they will solve your issue.

If possible then send us some screen shots of problematic area. It will be easier for us to solve issue soon.

So send us following information.

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we will check it.

Waiting for your reply.

 

it automagically fixed itself. No idea which of my de/re-installs did the trick.