Your LimeSurvey version: Version 3.17.6
Own server or LimeSurvey hosting: "Own server" (Hosted by my uni)
Theme: 
==================
Hi,
I have this really weird issue where questions that contain a relevance equation disappear. I have a hidden equation question which generates a random number between 1-3, and I have 3 text display questions with relevance equations that only appear on one of the three numbers. Below I included a screenshot with my setup. What should happen is that one of the three questions should appear, but instead not a single question appears and the entire questiongroup gets skipped. I've tried quite a lot but nothing seems to work, I'm not sure if this is a bug or if I did something wrong, any help would be greatly appreciated. Thanks!! 

 

To answer the first question I'll probably get: The "Always hide this question" option is turned off for all three questions.

Seems to be a small typo issue or so.
Please send this part of your survey as LSS export.

Joffm

Thanks for your reply! I didn't know how to export only this part of my survey so I took the full export, I hope that's okay.

 

You probably copied the code of the randnumber generation.

There is HTML code in the text. Remove it.

<pre>
{if(is_empty(randnumber.NAOK),rand(1,3),randnumber.NAOK)}</pre>

<p> </p>

And 

I didn't know how to export only this part of my survey

You copy the survey, remove all not related questions and send this survey as LSS.
But such a small survey is fine.

Joffm
 

Yess this was the problem! Thanks a lot, this really helped me

So for anyone else who has a problem of relevance questions disappearing: check if there isn't any HTML code in the random number generator!