Re: Launcher will not UNINSTALL any sims3pack files
@Sandraelle Try uninstalling while using Method by Mell, described here:
https://sims3.crinrict.com/en/2011/01/tutorial-how-to-get-rid-of-unwanted-custom-content.html
Sometimes the launcher behaves better if it only has one .dbc or .ebc file to deal with at a time. Please also keep in mind that for some Store content, individual items cannot be uninstalled separately, for example I found I couldn't remove the overalls that come bundled with Riverview, much to my disappointment. Trying to do so should throw an error, but it's also possible the launcher would trip over itself and not acknowledge that the process didn't work.
If this doesn't help, then the only fixes would be to delete the entire .dbc or .ebc file, and reinstall the content you want to keep; to edit the file with a tool like S3PE, if that even works (it's beyond my expertise); or if the items are CAS parts, to blacklist them with NRaas Dresser.