Fix setLanguage, check whether keys are valid languages (renderPageBu…

…ilderBlock uses pageData without language data)

src/Modules/GrapesJS/PageRenderer.php

@@ -81,10 +81,22 @@ public function __construct(ThemeContract $theme, PageContract $page, $forPageBu
      */
     public function setLanguage($language)
     {
+        // if the given language is unknown, default the set language to the first available language
+        $blockKeysAreLanguages = true;
         $supportedLanguages = array_keys($this->pageData['blocks'] ?? []);
-        if (! in_array($language, $supportedLanguages)) {
-            $language = $supportedLanguages[0] ?? $language;
+        // check whether keys are valid languages (renderPageBuilderBlock uses pageData without language data)
+        foreach ($supportedLanguages as $supportedLanguage) {
+            if (strlen($supportedLanguage) > 5) {
+                $blockKeysAreLanguages = false;
+                break;
+            }
+        }
+        if ($blockKeysAreLanguages) {
+            if (! in_array($language, $supportedLanguages)) {
+                $language = $supportedLanguages[0] ?? $language;
+            }
         }
+
         $this->language = $language;
         $this->pageBlocksData = $this->getStoredPageBlocksData();
         $this->shortcodeParser->setLanguage($language);