Unknown file encoding despite OnlyOffice installed and configured


I have a query regarding a technical issue that I’m facing. I have two machines, Machine A and Machine B, where I have different services running. In Machine A, I have Nginx Proxy Manager and OnlyOffice running inside Docker. And in Machine B, I have Seafile running inside Docker as well.

I have set up domain names for both services - “https ://office.mydomain.com” for OnlyOffice and “https ://seafile.mydomain.com” for Seafile.

To integrate OnlyOffice with Seafile, I followed the instructions (https ://manual.seafile.com/deploy/only_office/#configure-seafile-server) provided in the documentation. I made some changes in the seahub_setting.py file as well, which I’ll paste below:

# -*- coding: utf-8 -*-
SECRET_KEY = "severkey'"
SERVICE_URL = "https://seafile.mydomain.com"
CSRF_TRUSTED_ORIGINS = ["https://seafile.mydomain.com"]

    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'seahub_db',
        'USER': 'seafile',
        'PASSWORD': 'password',
        'HOST': 'db',
        'PORT': '3306',
        'OPTIONS': {'charset': 'utf8mb4'},

    'default': {
        'BACKEND': 'django_pylibmc.memcached.PyLibMCCache',
        'LOCATION': 'memcached:11211',
    'locmem': {
        'BACKEND': 'django.core.cache.backends.locmem.LocMemCache',
TIME_ZONE = 'Europe/Paris'
FILE_SERVER_ROOT = "https://seafile.mydomain.com/seafhttp"

# Enable OnlyOffice
ONLYOFFICE_APIJS_URL = 'https://office.mydomain.com/web-apps/apps/api/documents/api.js'
ONLYOFFICE_FILE_EXTENSION = ('doc', 'docx', 'ppt', 'pptx', 'xls', 'xlsx', 'odt', 'fodt', 'odp', 'fodp', 'ods', 'fods')
ONLYOFFICE_EDIT_FILE_EXTENSION = ('docx', 'pptx', 'xlsx')

# Enable force save to let user can save file when he/she press the save button on OnlyOffice file edit page.

# if JWT enabled
ONLYOFFICE_JWT_SECRET = 'onlyofficesecret'

I tried VERIFY_ONLYOFFICE_CERTIFICATE = True. I have checked that I am able to reach the https://office.mydomain.com/web-apps/apps/api/documents/api.js URL successfully. Additionally, I have verified the “Online Preview” settings and made sure that the proper extensions were here.

But unfortunately, I am still experiencing some issues. When I try to open a .doc or .docx file, it shows “Unknown file encoding”, and when I try to open a .xls or .xlsx file, it just displays a blank page.

I would really appreciate any assistance you can provide with this matter. Thank you so much in advance!