Will you be updating. I attempted to run Board3 version 2.1.0 on my test forum and got the following error. (Yes I did purge the forum cache.)
phpBB encountered an error building the container due to an installed extension. For this reason, all extensions have been temporarily disabled. Please try purging your forum cache. All extensions will automatically be re-enabled once the container error is resolved. If this error continues, please visit phpBB.com for support.
Exception: The file "/var/www/html/astronomy.hopto.org/ext/board3/portal/config/services.yml" does not contain valid YAML: The reserved indicator "@" cannot start a plain scalar; you need to quote the scalar at line 12 (near "- @board3.portal.columns").
#0 /var/www/html/astronomy.hopto.org/vendor/symfony/dependency-injection/Loader/YamlFileLoader.php(117): Symfony\Component\DependencyInjection\Loader\YamlFileLoader->loadFile('/var/www/html/a...')
#1 /var/www/html/astronomy.hopto.org/phpbb/extension/di/extension_base.php(99): Symfony\Component\DependencyInjection\Loader\YamlFileLoader->load('services.yml')
#2 /var/www/html/astronomy.hopto.org/phpbb/extension/di/extension_base.php(63): phpbb\extension\di\extension_base->load_services(Object(Symfony\Component\DependencyInjection\Compiler\MergeExtensionConfigurationContainerBuilder))
#3 /var/www/html/astronomy.hopto.org/vendor/symfony/dependency-injection/Compiler/MergeExtensionConfigurationPass.php(71): phpbb\extension\di\extension_base->load(Array, Object(Symfony\Component\DependencyInjection\Compiler\MergeExtensionConfigurationContainerBuilder))
#4 /var/www/html/astronomy.hopto.org/vendor/symfony/http-kernel/DependencyInjection/MergeExtensionConfigurationPass.php(39): Symfony\Component\DependencyInjection\Compiler\MergeExtensionConfigurationPass->process(Object(Symfony\Component\DependencyInjection\ContainerBuilder))
#5 /var/www/html/astronomy.hopto.org/vendor/symfony/dependency-injection/Compiler/Compiler.php(140): Symfony\Component\HttpKernel\DependencyInjection\MergeExtensionConfigurationPass->process(Object(Symfony\Component\DependencyInjection\ContainerBuilder))
#6 /var/www/html/astronomy.hopto.org/vendor/symfony/dependency-injection/ContainerBuilder.php(789): Symfony\Component\DependencyInjection\Compiler\Compiler->compile(Object(Symfony\Component\DependencyInjection\ContainerBuilder))
#7 /var/www/html/astronomy.hopto.org/phpbb/di/container_builder.php(203): Symfony\Component\DependencyInjection\ContainerBuilder->compile()
#8 /var/www/html/astronomy.hopto.org/common.php(115): phpbb\di\container_builder->get_container()
#9 /var/www/html/astronomy.hopto.org/adm/index.php(23): require('/var/www/html/a...')
#10 {main}