I’ve known about this problem for quite a while. Ever since a few updates ago when they added the new preview feature, I’ve noticed a few of my themes don’t show up in the preview. I never really worried about it because it obviously doesn’t have any adverse effects on the actual performance of the theme. Now that I’ve been giving my themes away and people have been asking me all kinds of questions, one question I’ve had several times is – why is the preview showing a blank screen?
The answer is actually really weird and simple. I didn’t actually figure this out until yesterday, but the reason the preview is blank – on some themes – is because WordPress doesn’t like the folder the theme is in to have a space in the name. For example my WP Contempo theme does not show a preview. The folder that WP Contempo comes in simply says WP Contempo.
How to fix the problem?
So easy. All you have to do is rename the folder to remove the space. So I changed my WP Contempo folder to WP_Contempo, the preview worked just fine. There’s 2 ways you can do it. If you use something like Dreamweaver, where you can edit files on a server, just navigate to where the theme folder is stored and add the _. Alternatively, you can also redownload the theme, unzip it and rename the folder to add the _, then upload the theme. It won’t matter if you already have the same theme with the space as well.
Now that I know this, I’ll be making sure that all my future releases follow the proper folder naming convention so there won’t be any more problems with the preview.