Hello everyone,

I am trying to upgrade my Odoo database from version 18.0+e to 18.4, but the process fails with an error.

The system throws an odoo.tools.convert.ParseError while attempting to load a data file, specifically mail_template_data.xml from the documents module. This appears to be a syntax error within the QWeb template code.

Here is the full traceback from the log:

Traceback (most recent call last):
  File "/home/odoo/src/odoo/saas-18.4/odoo/service/server.py", line 1410, in preload_registries
    registry = Registry.new(dbname, update_module=update_module, install_modules=config['init'], upgrade_modules=config['update'])
  File "<decorator-gen-6>", line 2, in new
  File "/home/odoo/src/odoo/saas-18.4/odoo/tools/func.py", line 89, in locked
    return func(inst, *args, **kwargs)
  File "/home/odoo/src/odoo/saas-18.4/odoo/orm/registry.py", line 175, in new
    load_modules(
  File "/home/odoo/src/odoo/saas-18.4/odoo/modules/loading.py", line 450, in load_modules
    load_module_graph(
  File "/home/odoo/src/odoo/saas-18.4/odoo/modules/loading.py", line 226, in load_module_graph
    load_data(env, idref, 'update', kind='data', package=package)
  File "/home/odoo/src/odoo/saas-18.4/odoo/modules/loading.py", line 79, in load_data
    tools.convert_file(env, package.name, filename, idref, mode, noupdate, kind)
  File "/home/odoo/src/odoo/saas-18.4/odoo/tools/convert.py", line 628, in convert_file
    convert_xml_import(env, module, fp, idref, mode, noupdate)
  File "/home/odoo/src/odoo/saas-18.4/odoo/tools/convert.py", line 709, in convert_xml_import
    obj.parse(doc.getroot())
  File "/home/odoo/src/odoo/saas-18.4/odoo/tools/convert.py", line 614, in parse
    self._tag_root(de)
  File "/home/odoo/src/odoo/saas-18.4/odoo/tools/convert.py", line 557, in _tag_root
    f(rec)
  File "/home/odoo/src/odoo/saas-18.4/odoo/tools/convert.py", line 568, in _tag_root
    raise ParseError(msg) from None  # Restart with "--log-handler odoo.tools.convert:DEBUG" for complete traceback
odoo.tools.convert.ParseError: while parsing /home/odoo/src/enterprise/saas-18.4/documents/data/mail_template_data.xml:228
Oops! We couldn't save your template due to an issue with this value: <table border="0" cellpadding="0" cellspacing="0" style="padding-top: 16px; background-color: #F1F1F1; font-family:Verdana, Arial,sans-serif; color: #454748; width: 100%; border-collapse:separate;"> ... (template content) ... </table>
. Correct it and try again.

View error context:
'-no context-'

I'm having trouble identifying the exact syntax error within the XML that is causing the parser to fail. Could anyone please help point out the issue and suggest a fix?

Thank you in advance for your help!