plugin import error with partner

Read a plugin with partner entry raise an error:

2026.02.12 15:03:23 ERROR     [bots.webserver] Traceback (most recent call last):
  File "E:\Data\bots_dev\.venv\Lib\site-packages\bots\pluglib.py", line 180, in read_plugin
    read_index2database(pluglist)
    ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^
  File "E:\Data\bots_dev\.venv\Lib\site-packages\bots\pluglib.py", line 467, in read_index2database
    obj = getattr(dbobject, key)
TypeError: attribute name must be string, not 'NoneType'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "E:\Data\bots_dev\.venv\Lib\site-packages\bots\views.py", line 1304, in plugin
    plugreport = pluglib.read_plugin(request.FILES["file"].temporary_file_path())
  File "E:\Data\bots_dev\.venv\Lib\site-packages\bots\pluglib.py", line 183, in read_plugin
    raise PluginError(
        _('Error writing plugin to database. Nothing is written. Error:\n%(txt)s'), {'txt': txt}
    ) from exc
bots.exceptions.PluginError: Error writing plugin to database. Nothing is written. Error:
TypeError: attribute name must be string, not 'NoneType'


2026.02.12 15:03:23 ERROR     [bots.webserver] Error occured while reading plugin "plugin_20260212.zip": TypeError: attribute name must be string, not 'NoneType'

The above exception was the direct cause of the following exception:

bots.exceptions.PluginError: Error writing plugin to database. Nothing is written. Error:
TypeError: attribute name must be string, not 'NoneType'