Is this module PHP8 compatible?

I just tested setting up Drupal 9 with the Insert module from the branch 8.x-2.x on PHP 7.4 and then switching to PHP 8. I did not experience a particular issue, not in general, and neither related to the Insert module. It would be interesting to examine the logs when that error appears, that should give a good hint about the issue.

Thanks for the patch, it does not look to be PHP 8 related unless I miss out on something; but it might make sense to have a check there anyway. I attached an optimised version, because it would not make sense to even process the foreach when there are no $text_formats if that is indeed the problem.

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

I just encountered this same error when trying to add a new page or block on a newly created site. Running Drupal 9.5.7, PHP 8.1.14, Insert 8.x-2.0-beta3. I did not yet try your patch. You had stated that it might be helpful to see the log messages, so here are the dumps of the 2 error messages I got. I'd be interested in knowing if you think your patch would still apply.

Warning: Undefined array key "drupalExternalPlugins" in insert_editor_js_settings_alter() (line 833 of /code/web/modules/contrib/insert/insert.module)

#0 /code/web/core/includes/bootstrap.inc(347): _drupal_error_handler_real(2, 'Undefined array...', '/code/web/modul...', 833)
#1 /code/web/modules/contrib/insert/insert.module(833): _drupal_error_handler(2, 'Undefined array...', '/code/web/modul...', 833)
#2 /code/web/core/lib/Drupal/Core/Extension/ModuleHandler.php(562): insert_editor_js_settings_alter(Array, NULL, NULL)
#3 /code/web/core/modules/editor/src/Plugin/EditorManager.php(88): Drupal\Core\Extension\ModuleHandler->alter('editor_js_setti...', Array)
#4 /code/web/core/modules/editor/src/Element.php(100): Drupal\editor\Plugin\EditorManager->getAttachments(Array)
#5 [internal function]: Drupal\editor\Element->preRenderTextFormat(Array)
#6 /code/web/core/lib/Drupal/Core/Security/DoTrustedCallbackTrait.php(101): call_user_func_array(Array, Array)
#7 /code/web/core/lib/Drupal/Core/Render/Renderer.php(788): Drupal\Core\Render\Renderer->doTrustedCallback(Array, Array, 'Render #pre_ren...', 'exception', 'Drupal\\Core\\Ren...')
#8 /code/web/core/lib/Drupal/Core/Render/Renderer.php(374): Drupal\Core\Render\Renderer->doCallback('#pre_render', Array, Array)
#9 /code/web/core/lib/Drupal/Core/Render/Renderer.php(204): Drupal\Core\Render\Renderer->doRender(Array, false)
#10 /code/web/core/lib/Drupal/Core/Template/TwigExtension.php(479): Drupal\Core\Render\Renderer->render(Array)
#11 /tmp/rolling/4a6f9b5/twig/6442aaa046ece_field-multiple-value-form_ds57qloNMUETHurvFKNX-za-X/UXcq92eApIyaFd_9jU2PsSbYTrS9Dlq25M0HUjeWgsU.php(89): Drupal\Core\Template\TwigExtension->escapeFilter(Object(Drupal\Core\Template\TwigEnvironment), Array, 'html', NULL, true)
#12 /code/vendor/twig/twig/src/Template.php(405): __TwigTemplate_d93c6c9fa59ad0649a07dcce1924ac9a->doDisplay(Array, Array)
#13 /code/vendor/twig/twig/src/Template.php(378): Twig\Template->displayWithErrorHandling(Array, Array)
#14 /code/vendor/twig/twig/src/Template.php(390): Twig\Template->display(Array)
#15 /code/web/core/themes/engines/twig/twig.engine(55): Twig\Template->render(Array)
#16 /code/web/core/lib/Drupal/Core/Theme/ThemeManager.php(384): twig_render_template('core/themes/cla...', Array)
#17 /code/web/core/lib/Drupal/Core/Render/Renderer.php(433): Drupal\Core\Theme\ThemeManager->render('field_multiple_...', Array)
#18 /code/web/core/lib/Drupal/Core/Render/Renderer.php(446): Drupal\Core\Render\Renderer->doRender(Array)
#19 /code/web/core/lib/Drupal/Core/Render/Renderer.php(446): Drupal\Core\Render\Renderer->doRender(Array)
#20 /code/web/core/lib/Drupal/Core/Render/Renderer.php(204): Drupal\Core\Render\Renderer->doRender(Array, false)
#21 /code/web/core/lib/Drupal/Core/Template/TwigExtension.php(479): Drupal\Core\Render\Renderer->render(Array)
#22 /tmp/rolling/4a6f9b5/twig/6442aaa046ece_node-edit-form.html.twig_6IvRpo8LMM79vlgE1EN6FQKYH/-LUlf70mQ5q_r3jRYdvRndx7paIbZSz8jScARe-tL-U.php(44): Drupal\Core\Template\TwigExtension->escapeFilter(Object(Drupal\Core\Template\TwigEnvironment), Array, 'html', NULL, true)
#23 /code/vendor/twig/twig/src/Template.php(405): __TwigTemplate_8d7605f11e792d80e3297ebd3db6e904->doDisplay(Array, Array)
#24 /code/vendor/twig/twig/src/Template.php(378): Twig\Template->displayWithErrorHandling(Array, Array)
#25 /code/vendor/twig/twig/src/Template.php(390): Twig\Template->display(Array)
#26 /code/web/core/themes/engines/twig/twig.engine(55): Twig\Template->render(Array)
#27 /code/web/core/lib/Drupal/Core/Theme/ThemeManager.php(384): twig_render_template('core/themes/cla...', Array)
#28 /code/web/core/lib/Drupal/Core/Render/Renderer.php(433): Drupal\Core\Theme\ThemeManager->render('node_edit_form', Array)
#29 /code/web/core/lib/Drupal/Core/Render/Renderer.php(204): Drupal\Core\Render\Renderer->doRender(Array, false)
#30 /code/web/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(242): Drupal\Core\Render\Renderer->render(Array, false)
#31 /code/web/core/lib/Drupal/Core/Render/Renderer.php(580): Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}()
#32 /code/web/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(243): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
#33 /code/web/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(132): Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\CurrentRouteMatch))
#34 /code/web/core/lib/Drupal/Core/EventSubscriber/MainContentViewSubscriber.php(90): Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\CurrentRouteMatch))
#35 [internal function]: Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#36 /code/web/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(142): call_user_func(Array, Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#37 /code/vendor/symfony/http-kernel/HttpKernel.php(174): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view')
#38 /code/vendor/symfony/http-kernel/HttpKernel.php(81): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#39 /code/web/core/lib/Drupal/Core/StackMiddleware/Session.php(58): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#40 /code/web/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#41 /code/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#42 /code/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#43 /code/web/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#44 /code/web/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#45 /code/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#46 /code/web/core/lib/Drupal/Core/DrupalKernel.php(718): Stack\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#47 /code/web/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request))
#48 {main}

TypeError: array_keys(): Argument #1 ($array) must be of type array, null given in array_keys() (line 833 of /code/web/modules/contrib/insert/insert.module)

#0 /code/web/modules/contrib/insert/insert.module(833): array_keys(NULL)
#1 /code/web/core/lib/Drupal/Core/Extension/ModuleHandler.php(562): insert_editor_js_settings_alter(Array, NULL, NULL)
#2 /code/web/core/modules/editor/src/Plugin/EditorManager.php(88): Drupal\Core\Extension\ModuleHandler->alter('editor_js_setti...', Array)
#3 /code/web/core/modules/editor/src/Element.php(100): Drupal\editor\Plugin\EditorManager->getAttachments(Array)
#4 [internal function]: Drupal\editor\Element->preRenderTextFormat(Array)
#5 /code/web/core/lib/Drupal/Core/Security/DoTrustedCallbackTrait.php(101): call_user_func_array(Array, Array)
#6 /code/web/core/lib/Drupal/Core/Render/Renderer.php(788): Drupal\Core\Render\Renderer->doTrustedCallback(Array, Array, 'Render #pre_ren...', 'exception', 'Drupal\\Core\\Ren...')
#7 /code/web/core/lib/Drupal/Core/Render/Renderer.php(374): Drupal\Core\Render\Renderer->doCallback('#pre_render', Array, Array)
#8 /code/web/core/lib/Drupal/Core/Render/Renderer.php(204): Drupal\Core\Render\Renderer->doRender(Array, false)
#9 /code/web/core/lib/Drupal/Core/Template/TwigExtension.php(479): Drupal\Core\Render\Renderer->render(Array)
#10 /tmp/rolling/4a6f9b5/twig/6442aaa046ece_field-multiple-value-form_ds57qloNMUETHurvFKNX-za-X/UXcq92eApIyaFd_9jU2PsSbYTrS9Dlq25M0HUjeWgsU.php(89): Drupal\Core\Template\TwigExtension->escapeFilter(Object(Drupal\Core\Template\TwigEnvironment), Array, 'html', NULL, true)
#11 /code/vendor/twig/twig/src/Template.php(405): __TwigTemplate_d93c6c9fa59ad0649a07dcce1924ac9a->doDisplay(Array, Array)
#12 /code/vendor/twig/twig/src/Template.php(378): Twig\Template->displayWithErrorHandling(Array, Array)
#13 /code/vendor/twig/twig/src/Template.php(390): Twig\Template->display(Array)
#14 /code/web/core/themes/engines/twig/twig.engine(55): Twig\Template->render(Array)
#15 /code/web/core/lib/Drupal/Core/Theme/ThemeManager.php(384): twig_render_template('core/themes/cla...', Array)
#16 /code/web/core/lib/Drupal/Core/Render/Renderer.php(433): Drupal\Core\Theme\ThemeManager->render('field_multiple_...', Array)
#17 /code/web/core/lib/Drupal/Core/Render/Renderer.php(446): Drupal\Core\Render\Renderer->doRender(Array)
#18 /code/web/core/lib/Drupal/Core/Render/Renderer.php(446): Drupal\Core\Render\Renderer->doRender(Array)
#19 /code/web/core/lib/Drupal/Core/Render/Renderer.php(204): Drupal\Core\Render\Renderer->doRender(Array, false)
#20 /code/web/core/lib/Drupal/Core/Template/TwigExtension.php(479): Drupal\Core\Render\Renderer->render(Array)
#21 /tmp/rolling/4a6f9b5/twig/6442aaa046ece_node-edit-form.html.twig_6IvRpo8LMM79vlgE1EN6FQKYH/-LUlf70mQ5q_r3jRYdvRndx7paIbZSz8jScARe-tL-U.php(44): Drupal\Core\Template\TwigExtension->escapeFilter(Object(Drupal\Core\Template\TwigEnvironment), Array, 'html', NULL, true)
#22 /code/vendor/twig/twig/src/Template.php(405): __TwigTemplate_8d7605f11e792d80e3297ebd3db6e904->doDisplay(Array, Array)
#23 /code/vendor/twig/twig/src/Template.php(378): Twig\Template->displayWithErrorHandling(Array, Array)
#24 /code/vendor/twig/twig/src/Template.php(390): Twig\Template->display(Array)
#25 /code/web/core/themes/engines/twig/twig.engine(55): Twig\Template->render(Array)
#26 /code/web/core/lib/Drupal/Core/Theme/ThemeManager.php(384): twig_render_template('core/themes/cla...', Array)
#27 /code/web/core/lib/Drupal/Core/Render/Renderer.php(433): Drupal\Core\Theme\ThemeManager->render('node_edit_form', Array)
#28 /code/web/core/lib/Drupal/Core/Render/Renderer.php(204): Drupal\Core\Render\Renderer->doRender(Array, false)
#29 /code/web/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(242): Drupal\Core\Render\Renderer->render(Array, false)
#30 /code/web/core/lib/Drupal/Core/Render/Renderer.php(580): Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}()
#31 /code/web/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(243): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
#32 /code/web/core/lib/Drupal/Core/Render/MainContent/HtmlRenderer.php(132): Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\CurrentRouteMatch))
#33 /code/web/core/lib/Drupal/Core/EventSubscriber/MainContentViewSubscriber.php(90): Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object(Symfony\Component\HttpFoundation\Request), Object(Drupal\Core\Routing\CurrentRouteMatch))
#34 [internal function]: Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#35 /code/web/core/lib/Drupal/Component/EventDispatcher/ContainerAwareEventDispatcher.php(142): call_user_func(Array, Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view', Object(Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher))
#36 /code/vendor/symfony/http-kernel/HttpKernel.php(174): Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch(Object(Symfony\Component\HttpKernel\Event\ViewEvent), 'kernel.view')
#37 /code/vendor/symfony/http-kernel/HttpKernel.php(81): Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object(Symfony\Component\HttpFoundation\Request), 1)
#38 /code/web/core/lib/Drupal/Core/StackMiddleware/Session.php(58): Symfony\Component\HttpKernel\HttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#39 /code/web/core/lib/Drupal/Core/StackMiddleware/KernelPreHandle.php(48): Drupal\Core\StackMiddleware\Session->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#40 /code/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(106): Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#41 /code/web/core/modules/page_cache/src/StackMiddleware/PageCache.php(85): Drupal\page_cache\StackMiddleware\PageCache->pass(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#42 /code/web/core/lib/Drupal/Core/StackMiddleware/ReverseProxyMiddleware.php(48): Drupal\page_cache\StackMiddleware\PageCache->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#43 /code/web/core/lib/Drupal/Core/StackMiddleware/NegotiationMiddleware.php(51): Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#44 /code/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23): Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#45 /code/web/core/lib/Drupal/Core/DrupalKernel.php(718): Stack\StackedHttpKernel->handle(Object(Symfony\Component\HttpFoundation\Request), 1, true)
#46 /code/web/index.php(19): Drupal\Core\DrupalKernel->handle(Object(Symfony\Component\HttpFoundation\Request))
#47 {main}