Can't launch Qt project, exit code -1073741819 (0xC0000005)

The project is set up correctly I guess, I've got no build errors and all classes are being recognized. The problem is that when I add the line

ui->lineEdit->setCompleter(completer);

that should set the completer for my lineEdit the application won't launch and it shows an output error

Process finished with exit code -1073741819 (0xC0000005)

Here are the project files

.pro

######################################################################
# Automatically generated by qmake (3.1) Thu Jul 18 13:48:43 2019
######################################################################

TEMPLATE = app
TARGET = "Laboratorio 5"
INCLUDEPATH += .
QT += gui core widgets

# The following define makes your compiler warn you if you use any
# feature of Qt which has been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

# Input
HEADERS += DiskUsageAnalyzer.h FileSystemModel.h
FORMS += DiskUsageAnalyzer.ui
SOURCES += DiskUsageAnalyzer.cpp FileSystemModel.cpp main.cpp

main.cpp

#include "DiskUsageAnalyzer.h"

int main(int argc, char** argv) {
    QApplication application(argc, argv);
    DiskUsageAnalyzer diskUsageAnalyzer;

    diskUsageAnalyzer.show();

    return application.exec();
}

FileSystemModel.h

#include <QtWidgets>

class FileSystemModel : public QFileSystemModel {

    Q_OBJECT


public:
    explicit FileSystemModel(QObject *parent = nullptr);

    QVariant data(const QModelIndex &index, int role) const override;

};

FileSystemModel.cpp

#include "FileSystemModel.h"

FileSystemModel::FileSystemModel(QObject *parent) : QFileSystemModel(parent) {


}

QVariant FileSystemModel::data(const QModelIndex &index, int role) const {
    if (role == Qt::DisplayRole && index.column() == 0) {
        QString path  = QDir::toNativeSeparators(filePath(index));
        if (path.endsWith(QDir::separator()))
            path.chop(1);
        return path;
    }
    return QFileSystemModel::data(index, role);
}

DiskUsageAnalyzer.h

#include "ui_DiskUsageAnalyzer.h"
#include "FileSystemModel.h"


class DiskUsageAnalyzer : public QMainWindow {

    Q_OBJECT

private:
    Ui_DiskUsageAnalyzer *ui;
    FileSystemModel *dirModel;
    QCompleter *completer;

public:
    explicit DiskUsageAnalyzer(QWidget *parent = nullptr);

    ~DiskUsageAnalyzer() override;

public slots:


signals:


};

DiskUsageAnalyzer.cpp

#include "DiskUsageAnalyzer.h"

DiskUsageAnalyzer::DiskUsageAnalyzer(QWidget *parent) : QMainWindow(parent) {
    ui = new Ui::DiskUsageAnalyzer;
    dirModel = new FileSystemModel(this);
    dirModel->setRootPath("");
    completer = new QCompleter(this);
    ui->lineEdit->setCompleter(completer);
    ui->setupUi(this);

}

DiskUsageAnalyzer::~DiskUsageAnalyzer() {
    delete ui;
}

Sorry for not providing a minimal reproducible example but I'm new to Qt and I have no clue on how to reduce all files at minimum.