Tested just now: flat_style 1.1.10 installs perfectly
I then installed 2 extra styles.
With flat style still installed I could uninstall one of the new styles.
Then uninstalled flat-style and could uninstall the other extra style, and could install another style.
As KevC already mentioned: if the style was uploaded to an incorrect folder (it should be directly in /styles) it can't be detected as a style.
Spelling is freeware, which means you can use it for free.
On the other hand, it is not open source, which means you cannot change it or publish it in a modified form.
Time flies like an arrow, but fruit flies like a banana.
They're just zip files. You need the folders that are inside those.
Unzip them on your computer and upload those. The layout of those style folders you upload needs to look the same as the prosilver one.
-:|:- Support Request Template -:|:- "Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb"
Normal people… believe that if it ain’t broke, don’t fix it. Engineers believe that if it ain’t broke, it doesn’t have enough features yet. – Scott Adams
The flat-style/ contains everything needed.
The colour versions require flat-style/ to be installed as the colour sets only contain the /theme, style.cfg and license.txt. (no /template and no /contrib)
Spelling is freeware, which means you can use it for free.
On the other hand, it is not open source, which means you cannot change it or publish it in a modified form.
Time flies like an arrow, but fruit flies like a banana.