Warning: Erroneous data format for unserializing

This error appears when installing in the first paragraph. What am I doing wrong? Warning: Erroneous data format for unserializing 'Drupal\Core\Extension\Extension' in Drupal\Core\Cache\DatabaseBackend->prepareItem() (line 167 of core/lib/Drupal/Core/Cache/DatabaseBackend.php). Drupal\Core\Cache\DatabaseBackend->prepareItem(Object, ) (Line: 122) Drupal\Core\Cache\DatabaseBackend->getMultiple(Array, ) (Line: 92) Drupal\Core\Cache\DatabaseBackend->get('theme.active_theme.seven') (Line: 83) Drupal\Core\Theme\ThemeInitialization->getActiveThemeByName('seven') (Line: 346) theme_get_setting('features.favicon') (Line: 606) system_page_attachments(Array) (Line: 65) Drupal\Core\Render\BareHtmlPageRenderer->renderBarePage(Array, 'Choose language', 'install_page', Array) (Line: 76) Drupal\Core\ProxyClass\Render\BareHtmlPageRenderer->renderBarePage(Array, 'Choose language', 'install_page', Array) (Line: 1067) install_display_output(Array, Array) (Line: 167) install_drupal(Object) (Line: 44) Notice: unserialize(): Error at offset 354 of 34020 bytes in Drupal\Core\Cache\DatabaseBackend->prepareItem() (line 167 of core/lib/Drupal/Core/Cache/DatabaseBackend.php). Drupal\Core\Cache\DatabaseBackend->prepareItem(Object, ) (Line: 122) Drupal\Core\Cache\DatabaseBackend->getMultiple(Array, ) (Line: 92) Drupal\Core\Cache\DatabaseBackend->get('theme.active_theme.seven') (Line: 83) Drupal\Core\Theme\ThemeInitialization->getActiveThemeByName('seven') (Line: 346) theme_get_setting('features.favicon') (Line: 606) system_page_attachments(Array) (Line: 65) Drupal\Core\Render\BareHtmlPageRenderer->renderBarePage(Array, 'Choose language', 'install_page', Array) (Line: 76) Drupal\Core\ProxyClass\Render\BareHtmlPageRenderer->renderBarePage(Array, 'Choose language', 'install_page', Array) (Line: 1067) install_display_output(Array, Array) (Line: 167) install_drupal(Object) (Line: 44) The website encountered an unexpected error. Please try again later. Error: Call to a member function getLogo() on bool in theme_get_setting() (line 346 of core/includes/theme.inc). theme_get_setting('features.favicon') (Line: 606) system_page_attachments(Array) (Line: 65) Drupal\Core\Render\BareHtmlPageRenderer->renderBarePage(Array, 'Choose language', 'install_page', Array) (Line: 76) Drupal\Core\ProxyClass\Render\BareHtmlPageRenderer->renderBarePage(Array, 'Choose language', 'install_page', Array) (Line: 1067) install_display_output(Array, Array) (Line: 167) install_drupal(Object) (Line: 44)