Error 500 Uploading using Vue-Clip and GD Library

[jasperf]

I am using vue-clip inside a Laravel project. Works well locally running Laradock with ImageMagick. But when I use built in GD Library (for image resizing) I get errors 500.

file ImageUAndSModal.vue takes care of the uploading and selection and this Vue method deals with the completed uploads at

complete: function (file, status, xhr) {
                if (xhr.status === 200) {
                    this.handleSuccess(xhr.response);
                } else {
                    this.handleFailed(xhr.response);
                }
            },

            handleFailed: function(res) {
                let error = JSON.parse(res);

                if (error && error.message) {
                    EventBus.$emit('showError', error.message);
                } else {
                    EventBus.$emit('showError', 'Image could not be uploaded to server.');
                }
            },

            handleSuccess: function(response) {
                EventBus.$emit('showSuccess', 'Image successfully uploaded to server.');
                var newFile = JSON.parse(response);
                this.uploads.push(newFile.data);
            }

It diligently shows the file cannot be uploaded and in the console I see an error 500

Failed to load resource: the server responded with a status of 500 ()

all the time at

Dropzone.prototype.submitRequest = function(xhr, formData, files) {
	      return xhr.send(formData);
	    };
                            ,

using Chrome inspector. Adding

timeout: 90000, /*milliseconds*/

to ..../form-dropzone.js does not help and earlier PHP.ini / laravel.ini tweaks for more time-out time and RAM do not seem to help as of yet. Wrote all about the PHP FPM tweaks at laradock/laradock#1969 .

Have not solved this in 2 months now. Checked in with Laradock, Nginx and Docker, but no responses yet and as this is something I could perhaps with better JS/Vue foo I decided to ask here. I need better error reporting to understand why I get this server error 500. How do you recommend me dealing with this?