I have Nginx as reverse proxy to a backend server that proxies multiple applications.

While everything works for the most of the time, here I am experiencing JS error Uncaught TypeError: Cannot read properties of undefined (reading ‘transform’).

When accessing backend directly, of course everything is OK, and as well. As soon as I involve nginx, error is there.

Nginx config as below:

server {
listen 443 ssl;
server_name myproxydomain.com;

ssl_certificate /path/to/my/ssl_certificate.crt;
ssl_certificate_key /path/to/my/ssl_certificate.key;

location / {
proxy_pass https://backenddomain.com;
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;

sub_filter_types *;
sub_filter_once off;
sub_filter 'backenddomain.com' 'myproxydomain.com';
> > >     }
> > > }

Part of JS code error is caught:

    function internalContinueImporting() {
    if (globalImporter.state != Importer.State.Idle) {
        var ret = globalImporter.Advance(JsonsToImport, globalGamePath);
        LoaderProgress.Import_Current = globalImporter.currentProgress;
        if (ret.isDone && allGameJSONSadded) {
            LoaderProgress.Import_Current = globalImporter.totalNumberOfSteps;
            globalImporter.clear();
            var parent = ret.objects[JsonTypes.indexOf(0)].GetComponentsInChildren(LocalizationRoot, true)[0].transform;
            var GUIGo = ret.objects[JsonTypes.indexOf(1)].transform;
            var commonExtraGo = GUIGo.children[GUIGo.children.length - 1];
            commonExtraGo.SetParent(parent, false);
            GUIGo.SetParent(parent, false);
            for (var i = 0; i < ret.objects.length; ++i)
                if (JsonTypes[i] > 1)
                    ret.objects[i].transform.SetParent(parent, false);
            globalRuntime.addNewSceneRoot(ret.objects[JsonTypes.indexOf(0)]);
            mainGameJsonData = null;
            GUIJsonData = null;
            mainResources = null;
            otherResources = null;
            GUIResources = null;
            modulesJsonData = null
        }
    }
}

I have tried various configuration changes, but nothing seems to helped so far. I am hoping to find a solution or at least some clue in the right direction.

Also, all files, especially JS ones are loading properly using nginx.

I am using some sub_filter directives, and they are working as intended. (Compared outcome with another proxy server that seems to work correctly)