Catchable fatal error: Object of class stdClass could not be converted to string

Hello,

I am testing your plugin Usergroup Selector. Thank you for this.

The field is shown and the user is saved with the groups I selected. But: I get this message while registration: Catchable fatal error: Object of class stdClass could not be converted to string in /joomla/libraries/joomla/form/fields/checkboxes.php on line 161

Hello Astrid9,

Thanks for contacting us.

Can you please let us know which joomla version are you using with our plugin ?

Thank you. Here are my system details:



PHP erstellt für Linux astrid-TravelMate-5760G 4.15.0-65-generic #74-Ubuntu SMP Tue Sep 17 17:06:04 UTC 2019 x86_64
Datenbanktyp mysql
Datenbankversion 5.7.27-0ubuntu0.18.04.1
Datenbankzeichensatz utf8_general_ci
Datenbankverbindungszeichensatz utf8mb4_general_ci
PHP-Version 7.2.19-0ubuntu0.18.04.2
Webserver Apache/2.4.29 (Ubuntu)
PHP-Interface für den Webserver apache2handler
Joomla!-Version Joomla! 3.9.12 Stable [ Amani ] 24-September-2019 15:00 GMT
Joomla!-Plattform-Version Joomla Platform 13.1.0 Stable [ Curiosity ] 24-Apr-2013 00:00 GMT
Browsererkennung Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:69.0) Gecko/20100101 Firefox/69.0

I just found out something.
One sees the error message described above only if another error occurs.

I have tested the extension locally. No e-mail function is installed here. So I get an error, that no email could be send. Beside this error I saw the here mentioned error.

I have just installed the extension on another computer with active email function. Here you will be forwarded immediately while registration. That's why you can not see the here mentioned error.