I have the same issue as this person: Dictionary for TeXstudio: “No dictionary Available” with the exception, that I have the dictionaries. I also downloaded some, only to check if mine don't work. But it seems to be an issue of TeXstudio, because it finds the dictionaries when I give it the right path (under Options>Configure TexStudio>General>Dictionary), but when I click check spelling it's still complaining, that there is no dictionary available. Does someone know what I'm doing wrong or how to solve this?
Do the dictionaries show up in the selection box "Default Dictionary" right below the setting where you specified your path? If not they are not loaded (probably because they are not valid).
The dictionaries are hunspell dictionaries consisting of two files:
.aff. Both need to be present. If you use the dictionaries provided in
.oxt files, you need to import them using the button in the options (or extract the
.oxt files manually, which are just renamed zip files).