office-addin-manifest export fails when localization file is referenced

[atremel]

Prerequisites

As per the docs (https://learn.microsoft.com/en-us/office/dev/add-ins/develop/localization?tabs=jsonmanifest), manifest localization can be done like so:

"localizationInfo": {
    "defaultLanguageTag": "en",
    "additionalLanguages": [
        {
            "languageTag": "de",
            "file": "de.json"
        }
    ]
},

the file de.json is in the manifest's directory, has the correct name and the correct contents as per the docs (see above).

• [ x ] I am running the latest version of Node and the tools
• [ x ] I checked the documentation and found no answer
• [ x ] I checked to make sure that this issue has not already been filed

Expected behavior

office-addin-manifest export should work. However, it fails.
This is because the translation file is not included in the manifest.zip, see code, only the main json will get zipped:

Office-Addin-Scripts/packages/office-addin-manifest/src/export.ts

Line 26 in 0c210e9

zip.addLocalFile(manifestPath, "", "manifest.json");

Current behavior

I get an error "File for languageTag de is missing from the package or path is pointed to a wrong file."

[canturan]

Is there any update on this topic.
I have the same issue. After I added the localization files, when I execute npm start to debug the add-in, I get the following error message, because the localization files are not added to the manifest.zip file.

[b-tosic]

I'm facing the same issue.
It seems that local sideloading is not possible with localization files.

Is there a solution for this?

[b-tosic]

Well, in case it is helpful to anyone, until the official fix is released this is how I made a workaround:
edit your local package file here:
\node_modules\office-addin-manifest\lib\export.js

locate function createZip and inside that function add localization file(s) zipping just below line that calls addIconFile.
Here is an example, new code is between MANUAL WORKAROUND BEGIN and MANUAL WORKAROUND END comments:

addIconFile((_b = manifest.icons) === null || _b === void 0 ? void 0 : _b.outline, manifestDir, zip);
//MANUAL WORKAROUND BEGIN

        if(manifest.localizationInfo !== undefined && 

           manifest.localizationInfo.additionalLanguages !== undefined){

            for(let localizationLang of manifest.localizationInfo.additionalLanguages){

                zip.addLocalFile(localizationLang.file, "", localizationLang.file);

            }

        }

//MANUAL WORKAROUND END

        return Promise.resolve(zip);

Now, next time you run locally (sideloading) manifest.zip will contain also localization files and it should work when switching languages in Office app.

Hopefully this helps someone...