WP theme preview’s bug
There’s time when you want to preview a new downloaded WordPress theme before activating it, you found out that you cannot preview, it shows only a blank white page. Or better yet, those who develop WordPress theme, when you finish the hardest work designing and coding it into WordPress, found out you cannot preview it, only manage to activate it. So what you’re going to do?
I recently notice the differences of it. Since I have more than 100+ themes developed, all with different names. I can only preview some themes but some, I have to activate it and do correction. Now no more, cause I finally found the differences of it 
Rename is all it need to be preview. WordPress engine doesn’t like the folder with space (eg: my theme) or even the hyphen (eg: my-theme), they don’t want to preview those folder name. Only name with underscore (eg: my_theme) or better yet one word (eg: mytheme). 
Hi and thanks for this tip, I doubt many others knew why. I guess you had to investigate and figure it out for yourself.
Well done again
I don’t think it’s necessary to find out why, as long as it works by renaming, should be no problem for wp theme designer…