Error on simplytest.me that is "The website encountered an unexpected error. Please try again later.

Created same issue on simplytest.me project if it will be handled from simplytest.me.

https://www.drupal.org/project/simplytest/issues/3394828 →

I have closed the issue in simplytestme as "works as designed". I've added some notes in there but it does install on D9 as long as you remember to include the amp module as a manual dependency (it's not in the theme's composer.json).

To theme won't work on D10 whilst it has a dependency on the deprecated stable theme.

Thank you @ravi kant
I am still getting error when i am enabling sub-theme ExAMPle Subtheme 8.x-3.1

I am getting below error in error log.

TypeError: Unsupported operand types: array + null in Drupal\big_pipe\Render\BigPipe->sendPlaceholders() (line 578 of /app/web/core/modules/big_pipe/src/Render/BigPipe.php)
#0 /app/web/core/modules/big_pipe/src/Render/BigPipe.php(305): Drupal\big_pipe\Render\BigPipe->sendPlaceholders(Array, Array, Object(Drupal\Core\Asset\AttachedAssets))
#1 /app/web/core/modules/big_pipe/src/Render/BigPipeResponse.php(112): Drupal\big_pipe\Render\BigPipe->sendContent(Object(Drupal\big_pipe\Render\BigPipeResponse))
#2 /app/vendor/symfony/http-foundation/Response.php(381): Drupal\big_pipe\Render\BigPipeResponse->sendContent()
#3 /app/web/index.php(20): Symfony\Component\HttpFoundation\Response->send()
#4 {main}

Closing as duplicate of https://www.drupal.org/project/amptheme/issues/3394313 🐛 Getting errors in drupal-10.1.5 and Drupal-9.5.11 Active