Class "EmailValidator\EmailValidator" not found

@rex.barkdoll that class is from the third-party library, did you install the module using composer? The library should have been automatically imported with it.

Thanks for your response.
Yes, I installed with Composer. I can try reinstalling again to see if that works.

Ok, so reinstalling worked. Not sure what happened on the initial install.

That said, I'm now receiving other errors:

Deprecated function: explode(): Passing null to parameter #2 ($string) of type string is deprecated in _unwanted_email_registration_filter_email() (line 61 of modules/contrib/unwanted_email_registration/unwanted_email_registration.module).
_unwanted_email_registration_filter_email(NULL) (Line: 57)
Drupal\unwanted_email_registration\UnwantedEmailRegistrationService->validateEmail('testemail@gmail.com') (Line: 44)
_unwanted_email_registration_form_validate(Array, Object)
call_user_func_array('_unwanted_email_registration_form_validate', Array) (Line: 82)
Drupal\Core\Form\FormValidator->executeValidateHandlers(Array, Object) (Line: 274)
Drupal\Core\Form\FormValidator->doValidateForm(Array, Object, 'user_register_form') (Line: 118)
Drupal\Core\Form\FormValidator->validateForm('user_register_form', Array, Object) (Line: 593)
Drupal\Core\Form\FormBuilder->processForm('user_register_form', Array, Object) (Line: 326)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 73)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 638)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 181)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 53)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 57)
Drupal\advban\AdvbanMiddleware->handle(Object, 1, 1) (Line: 50)
Drupal\ban\BanMiddleware->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object, 1, 1) (Line: 741)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

Error message
Warning: Undefined array key 1 in _unwanted_email_registration_filter_email() (line 63 of modules/contrib/unwanted_email_registration/unwanted_email_registration.module).
_unwanted_email_registration_filter_email('') (Line: 57)
Drupal\unwanted_email_registration\UnwantedEmailRegistrationService->validateEmail('testemail@gmail.com') (Line: 44)
_unwanted_email_registration_form_validate(Array, Object)
call_user_func_array('_unwanted_email_registration_form_validate', Array) (Line: 82)
Drupal\Core\Form\FormValidator->executeValidateHandlers(Array, Object) (Line: 274)
Drupal\Core\Form\FormValidator->doValidateForm(Array, Object, 'user_register_form') (Line: 118)
Drupal\Core\Form\FormValidator->validateForm('user_register_form', Array, Object) (Line: 593)
Drupal\Core\Form\FormBuilder->processForm('user_register_form', Array, Object) (Line: 326)
Drupal\Core\Form\FormBuilder->buildForm(Object, Object) (Line: 73)
Drupal\Core\Controller\FormController->getContentResult(Object, Object)
call_user_func_array(Array, Array) (Line: 123)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 638)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 124)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext(Array, Array) (Line: 97)
Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}() (Line: 181)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 53)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 32)
Drupal\big_pipe\StackMiddleware\ContentLength->handle(Object, 1, 1) (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 57)
Drupal\advban\AdvbanMiddleware->handle(Object, 1, 1) (Line: 50)
Drupal\ban\BanMiddleware->handle(Object, 1, 1) (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 36)
Drupal\Core\StackMiddleware\AjaxPageState->handle(Object, 1, 1) (Line: 51)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle(Object, 1, 1) (Line: 741)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

@rex.barkdoll that appears to be a problem with unwanted_email_registration rather than this email.

I suggest opening an issue for that module :)

I'll leave this issue open for a little while in case you come across something else that affects this module you would like help with.

Whoops, sorry about that. I guess I wasn't reading closely enough.

No worries mate, hope you got it sorted out :)

Feel free to reopen if you need more help, or a fresh ticket if you find something substantially different.

Automatically closed - issue fixed for 2 weeks with no activity.