There is a missing comma (,) in the abp.resourcemapping.js file of the @abp/luxon package.

If you create a solution with 3.2.0-rc.1, you need to perform the following steps;

1. Execute yarn (or npm install) in the root folder of your MVC UI project.
2. Open the file node_modules\@abp\luxon\abp.resourcemapping.js and change the content as shown below and save the changes:

module.exports = {
    mappings: {
        "@node_modules/luxon/build/global/*.*": "@libs/luxon/",
        "@node_modules/@abp/luxon/src/*.*": "@libs/abp/luxon/"
    }
}

3. execute the gulp (or yarn gulp) command.

This will add the missing /wwwroot/libs/luxon folder in your project.