CSS/Stylelint - E715: Dictionary required

[s1mp7e]

when opening css file an error appears:

Error detected while processing BufWritePost Autocommands for "*"..function
ale#events#SaveEvent[13]..ale#Queue[33]..<SNR>38_Lint[3]..ale#linter#Get[6].
.<SNR>40_GetLinterNames:
line   19:
E715: Dictionary required

specified processing of one format in the settings.

let g:ale_linters = {'css': ['stylelint']}

the stylelint package is installed globally, the .stylelintrc file is in the root of the project.
and this error pops up even when opening a simple .txt file.
how to set up ale linter to work only with css files and stylelint package?