Hi cheesegrits, thank you for your response.
I did as you told, and this is what I see on Network tab when I click Next button:
Name: index.php?option=com_fabrik&format=raw&task=form.ajax_validate&form_id=12
Status: 500
Type: xhr
Initiator: jquery.js?11b9e5d293a8603524d51d57f9bcddab:10254
Size: 4.5 KB
Time: 439 ms
If I click on the url marked red (index.php?option=com_fabrik&format=raw&task=form.ajax_validate&form_id=12), I can see the Preview and Response tab, and this is the error reported:
syntax error, unexpected '==' (T_IS_EQUAL), expecting ';'
.../components/com_fabrik/models/validation_rule.php(144) : eval()'d code:1
Call stack
# Function Location
1 () JROOT/components/com_fabrik/models/validation_rule.php(144) : eval()'d code:1
2 PlgFabrik_Validationrule->shouldValidate() JROOT/components/com_fabrik/models/form.php:2361
3 FabrikFEModelForm->validate() JROOT/components/com_fabrik/controllers/form.php:572
4 FabrikControllerForm->ajax_validate() JROOT/libraries/src/MVC/Controller/BaseController.php:710
5 Joomla\CMS\MVC\Controller\BaseController->execute() JROOT/components/com_fabrik/fabrik.php:181
6 require_once() JROOT/libraries/src/Component/ComponentHelper.php:381
7 Joomla\CMS\Component\ComponentHelper::executeComponent() JROOT/libraries/src/Component/ComponentHelper.php:356
8 Joomla\CMS\Component\ComponentHelper::renderComponent() JROOT/libraries/src/Application/SiteApplication.php:194
9 Joomla\CMS\Application\SiteApplication->dispatch() JROOT/libraries/src/Application/SiteApplication.php:233
10 Joomla\CMS\Application\SiteApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:267
11 Joomla\CMS\Application\CMSApplication->execute() JROOT/index.php:49
If I click on the Initator marked red (jquery.js?11b9e5d293a8603524d51d57f9bcddab:10254), I can see the following line (line 10254 of ../media/jui/js/jquery.js) marked as error in Sources tab:
xhr.send( ( options.hasContent && options.data ) || null );
The error reported is "Failed to load resource: the server responded with a status of 500 (Internal Server Error)"
I'm using Joomla 3.8.3 and Fabrik 3.8 with T3 blank template. If I switch to protostar, the issue is not solved.
Only rolling back from php 7.0 to php 5.6 solves the problem.
I hope you can help me figure it out.
Thanks a lot.