Form submit with notEmpty validation error gives js error

[chipperfield]

Joomla 4.2.9, Fabrik 4 gamma3, Apache, Windows10

On submit of a form with validation error (empty mandatory field where validation is set to NotEmpty), the return is to a blank screen with JS error:

blockuserinput.js:3 Uncaught ReferenceError: jQuery is not defined
at onFabrikReady (blockuserinput.js:3:565)

When the validated field has a value, the form submits OK.

 

[troester]

Frontend, backend? Upgraded F3? Which J! template?...

Enable J! error reporting ( a JS error is not a reason for a blank screen).

 

[chipperfield]

Sory, not enough info.
Front end standard Cassiopeia template, on a localhost site upgraded from J3 and upgraded for each Fabrik 4x release.
Screen is not blank, but no Fabrik content is rendered after JS error. Screen print attached with DebugJS enabled.

 

[troester]

Can you enable Joomla's error reporting (in Global Config set Error Reporting to System Default or Max).
How do you call the form (from a list, directly form menu, content plugin)?

 

[chipperfield]

Good suggestion - I think I now see this is my logic error, sorry for wasting your time.
The problem was that I also have a form plugin running OnBeforeLoad, which was executed when the form was returned after the validation failure.
The plugin returned false (correctly, because some of the form data had been updated). Thus the Fabrik rendering was stopped.
I do not known why the js errors appear, or whether there should be a more visible error result from this situation, but thank you for your input.