Why is TGM not compatible with sanitize_textarea_field?

[pierreamgabriel]

I updated my plugin to use the proper sanitization function for text areas, but it won't activate. TGM shows the following message when I try to install the plugin:

"The remote plugin package consists of more than one file, but the files are not packaged in a folder. Please contact the plugin provider and ask them to package their plugin according to the WordPress guidelines."

If I remove the sanitize_textarea_field() function from the code and it works fine.