Localization resources in another project not accessible (WPF, C#)

First of all: I am not very educated about disposing object and the ways to do it.

The project:

Currently I am working on a solution that includes an ASP.Net API, WPF and library project (all in .NET 6.0). The library contains .resx files to provide localized strings. I have implemented the localization according to this guide. This works pretty well except in some cases. The main problem is in the WPF project. I will simplify the namespaces to make them more accessible:

WPF project: My.Namespace.WPF
Library project: My.Namespace.Language

To get all supported languages, I use this class in My.Namespace.Language:

public class LanguageProvider
{
    public static IEnumerable<CultureInfo> GetSupportedLanguages()
    {
        List<CultureInfo> supportedLanguages = new();
        CultureInfo[] cultures = CultureInfo.GetCultures(CultureTypes.NeutralCultures);
        foreach (CultureInfo culture in cultures)
        {
            try
            {
                using ResourceSet? rs = Resources.Strings.ResourceManager.GetResourceSet(culture, true, false);
                if (rs is not null && culture.TwoLetterISOLanguageName != "iv")
                {
                    if (!supportedLanguages.Contains(culture))
                    {
                        supportedLanguages.Add(culture);
                    }
                }
                else if (culture.TwoLetterISOLanguageName == "en")
                {
                    supportedLanguages.Add(culture);
                }
            }
            catch (Exception)
            {

            }
        }

        return supportedLanguages;
    }
}

This project also contains the resource folder with Strings.resx and Strings.de.resx (namespace My.Namespace.Language.Resources). To get a string from the resources in my WPF project, I just use this:

string customText = My.Namespace.Language.Resources.Strings.sometext;

The problem:

All objects that are initalized after the first call of GetSupportedLanguages() cannot access the Strings and throw an ObjectDisposedException: Cannot access a closed resource set. Normally it is called before the MainWindow is initialized. So therefore I could not even display that. Do I have to implement the listing of available languages differently because the resources are disposed at some point?

Solution

Apparantly, you should not dispose the ResourceSet to be able to re-use the ResourceManager to get the resources. Remove using:

ResourceSet? rs = strings.ResourceManager.GetResourceSet(culture, true, false);