Can't delete 3 Slide Master

I have run across this myself. You can't delete Master Slides if they are being used. You will need to find the slide each is being used by and change it to a different Master or slide layout then you will be able to remove it. 

Not sure why you want to delete Masters. I have a lot of Master and slide groups I never use. They just sit in the background if I need on someday. 

Add a big red shap[e to a master and see what shows.

PhilMayor​ I love this idea, thanks

As PhilMayor​ said, adding a big, red shape to the Slide Master(s) that you want to delete is a great way to identify which slides use that master layout. 

I know about one weird instance when that red shape won't help. When you insert a slide that draws from a question blank, that placeholder is assigned a layout. However, because i shows questions when the course is viewed, you can't see what layout is being used, and you can't change the layout of the draw placeholder-slide. 

So, first, use the big, red shape trick to identify slides using the unwanted layout. If that doesn't work, go to any question-bank draws, and then do this:

• Delete the question-bank draw(s). 
• Delete the unwanted Slide Master(s). 
• Insert a new question-bank draw with the desired settings.

Thank you for your replies, but that is unfortunately not the point.

As written I have only 29 slides in the whole project. But if I look in the Master slide view and add all "this slide is used x times" I get 33 in total. Thats not possible because I only have 29 slides in the project. 

Even I tried the "huge red circle over the whole slide"-trick, but as you can see no slide has this circle.

As long as it is not possible to assign more than one layout to the same slide, there is obviously a strange behaviour.

With that type of "strange behavior," it's best to submit a case directly to the Articulate staff. You can do that here:  https://access.articulate.com/support/contact 

I see what you are saying. Don't understand what is happening. My first question is, have you run the presentation in Review to see if everything works. Id so and it does I wouldn't worry about it. If not what issues are you having? 

Next, If you can and would like to send me a copy, I will look it over and see what I can find for you. When and if I find an issue and resolve it I will contact you and go over it with you. 

Good luck, I know many of these projects have a lot of confidential information, so sharing is not possible.  

Hi TH-bf52b1b3-f6f​!

Sorry to hear you're having trouble deleting Master Slides from Storyline!

It's great to see all the help you've been receiving from the community so far. It would be easier to troubleshoot this type of issue if we could see a copy of the .story file you're working with. I've opened a support case on your behalf, and sent you a link you can use to share your file privately.

We'll delete it from our system as soon as we're finished, and we can continue the conversation through your case!