Hello Marton,
I'm sorry that you are experiencing this error.
This error occurs when the 'jQuery validation plugin' is not loaded or the jQuery-related scripts are loaded in an incorrect order.
Please check and make sure that the validation plugin is being loaded after the jQuery library.
See also 'Solution 2' here:
www.codeproject.com/Questions/5340881/Jq...te-is-not-a-function
Visforms uses the 'jQuery validation plugin' and its own extension (i.e. a plugin for the plugin: media/com_visforms/js/jquery.validate.min.js)
in numerous places to validate form data.
As for Visforms, its code ensures that the loading order is correct.
However, Visforms has no influence on how other extensions behave in this regard.
There are extensions that don't follow the rules.
The mentioned component may not use the recommended Joomla functions to load jQuery.
Or it intervenes in the loading process in another way that is not Joomla-compliant, for example
- by loading a jQuery version that is too old
- by redefining the jQuery runtime object or
- by late, unauthorized reloading of jQuery and/or the 'jQuery validation plugin' (see above).
Is it possible that the JavaScript error will disappear if you disable the mentioned component?
Please contact the publisher of the component mentioned, as Visforms is not the culprit at this point.
There are other topics in the forum with similar jQuery loading problems to yours.
In all cases it is a template or component that is messing up the loading of the libraries.
vi-solutions.de/en/forum/19-joomla-exten...-not-a-function#4856
vi-solutions.de/en/forum/19-joomla-exten...isabled?start=6#4679
Kind regards, Ingmar