If I I take away from the locales of a Site created from a Site Template, I cannot propagate my changes from the Site Template

Issue

When you create a Site based on a Site Template, change the default localization settings of a the created Site and take away from the available locales, further changes to the Site Template are not propagated to the Site.

Reproduction steps:

1. Go to Control Panel → System Settings → Infrastructure → Site Settings Configuration, check "Enable custom language settings for sites with template propagation", and save it
2. Create a dummy site template from Control Panel → Site Templates.('Dummy site template')
3. Go to Control Panel → Sites and create a new one based upon the 'Dummy site template'. ('Dummy site')
4. Go to the Site Settings page → Localization and activate the 'Define a custom default language and additional available languages for this site' option.
5. Leave 'English (United States)' as the default language and 'English (United States)' and 'Finnish (Finland)' as current languages. Save.
6. Add a new widget page to the 'Dummy site template' with the default values. ('Dummy page')
7. Open the 'Dummy site' home page.

Result: changes are not propagated and an ERROR is thrown:

2023-02-20 12:37:10.972 ERROR [liferay/background_task-4][LayoutSetPrototypeImportBackgroundTaskExecutor:166] Merge fail count increased to 1 for layout set prototype 44335
com.liferay.portal.kernel.exception.LocaleException: null
at com.liferay.exportimport.internal.controller.LayoutImportController.validateFile(LayoutImportController.java:655) ~[?:?]
at com.liferay.exportimport.internal.controller.LayoutImportController.importDataDeletions(LayoutImportController.java:158) ~[?:?]
at com.liferay.portlet.exportimport.service.impl.ExportImportLocalServiceImpl.importLayoutsDataDeletions(ExportImportLocalServiceImpl.java:266) ~[portal-impl.jar:?]
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?]
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
at com.liferay.portal.spring.aop.AopMethodInvocationImpl.proceed(AopMethodInvocationImpl.java:50) ~[portal-impl.jar:?]
at com.liferay.portal.spring.transaction.TransactionInterceptor.invoke(TransactionInterceptor.java:69) ~[portal-impl.jar:?]
at com.liferay.portal.spring.aop.AopMethodInvocationImpl.proceed(AopMethodInvocationImpl.java:57) ~[portal-impl.jar:?]
at com.liferay.portal.spring.aop.AopInvocationHandler.invoke(AopInvocationHandler.java:49) ~[portal-impl.jar:?]
at com.sun.proxy.$Proxy125.importLayoutsDataDeletions(Unknown Source) ~[?:?]
at com.liferay.exportimport.internal.background.task.LayoutSetPrototypeImportBackgroundTaskExecutor$LayoutImportCallable.call(LayoutSetPrototypeImportBackgroundTaskExecutor.java:280) ~[?:?]
at com.liferay.exportimport.internal.background.task.LayoutSetPrototypeImportBackgroundTaskExecutor$LayoutImportCallable.call(LayoutSetPrototypeImportBackgroundTaskExecutor.java:266) ~[?:?]
at com.liferay.portal.spring.transaction.BaseTransactionExecutor.execute(BaseTransactionExecutor.java:37) ~[portal-impl.jar:?]
at com.liferay.portal.spring.transaction.TransactionInvokerImpl.invoke(TransactionInvokerImpl.java:39) ~[portal-impl.jar:?]
at com.liferay.portal.kernel.transaction.TransactionInvokerUtil.invoke(TransactionInvokerUtil.java:28) ~[portal-kernel.jar:?]
at com.liferay.exportimport.internal.background.task.LayoutSetPrototypeImportBackgroundTaskExecutor.execute(LayoutSetPrototypeImportBackgroundTaskExecutor.java:130) [bundleFile:?]
at com.liferay.portal.background.task.internal.SerialBackgroundTaskExecutor.execute(SerialBackgroundTaskExecutor.java:63) [bundleFile:?]
at com.liferay.portal.kernel.backgroundtask.DelegatingBackgroundTaskExecutor.execute(DelegatingBackgroundTaskExecutor.java:41) [portal-kernel.jar:?]
at com.liferay.portal.background.task.internal.ThreadLocalAwareBackgroundTaskExecutor.execute(ThreadLocalAwareBackgroundTaskExecutor.java:72) [bundleFile:?]
at com.liferay.portal.background.task.internal.messaging.BackgroundTaskMessageListener.doReceive(BackgroundTaskMessageListener.java:120) [bundleFile:?]
at com.liferay.portal.kernel.messaging.BaseMessageListener.doReceive(BaseMessageListener.java:48) [portal-kernel.jar:?]
at com.liferay.portal.kernel.messaging.BaseMessageListener.receive(BaseMessageListener.java:34) [portal-kernel.jar:?]
at com.liferay.portal.kernel.messaging.InvokerMessageListener.receive(InvokerMessageListener.java:74) [portal-kernel.jar:?]
at com.liferay.portal.messaging.internal.ParallelDestination$1.run(ParallelDestination.java:56) [bundleFile:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
at java.lang.Thread.run(Thread.java:829) [?:?]
2023-02-20 12:37:11.040 ERROR [liferay/background_task-4][BackgroundTaskMessageListener:167] Unable to execute background task
com.liferay.portal.kernel.exception.LocaleException: null
at com.liferay.exportimport.internal.controller.LayoutImportController.validateFile(LayoutImportController.java:655) ~[?:?]
at com.liferay.exportimport.internal.controller.LayoutImportController.importDataDeletions(LayoutImportController.java:158) ~[?:?]
at com.liferay.portlet.exportimport.service.impl.ExportImportLocalServiceImpl.importLayoutsDataDeletions(ExportImportLocalServiceImpl.java:266) ~[portal-impl.jar:?]
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?]
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
at com.liferay.portal.spring.aop.AopMethodInvocationImpl.proceed(AopMethodInvocationImpl.java:50) ~[portal-impl.jar:?]
at com.liferay.portal.spring.transaction.TransactionInterceptor.invoke(TransactionInterceptor.java:69) ~[portal-impl.jar:?]
at com.liferay.portal.spring.aop.AopMethodInvocationImpl.proceed(AopMethodInvocationImpl.java:57) ~[portal-impl.jar:?]
at com.liferay.portal.spring.aop.AopInvocationHandler.invoke(AopInvocationHandler.java:49) ~[portal-impl.jar:?]
at com.sun.proxy.$Proxy125.importLayoutsDataDeletions(Unknown Source) ~[?:?]
at com.liferay.exportimport.internal.background.task.LayoutSetPrototypeImportBackgroundTaskExecutor$LayoutImportCallable.call(LayoutSetPrototypeImportBackgroundTaskExecutor.java:280) ~[?:?]
at com.liferay.exportimport.internal.background.task.LayoutSetPrototypeImportBackgroundTaskExecutor$LayoutImportCallable.call(LayoutSetPrototypeImportBackgroundTaskExecutor.java:266) ~[?:?]
at com.liferay.portal.spring.transaction.BaseTransactionExecutor.execute(BaseTransactionExecutor.java:37) ~[portal-impl.jar:?]
at com.liferay.portal.spring.transaction.TransactionInvokerImpl.invoke(TransactionInvokerImpl.java:39) ~[portal-impl.jar:?]
at com.liferay.portal.kernel.transaction.TransactionInvokerUtil.invoke(TransactionInvokerUtil.java:28) ~[portal-kernel.jar:?]
at com.liferay.exportimport.internal.background.task.LayoutSetPrototypeImportBackgroundTaskExecutor.execute(LayoutSetPrototypeImportBackgroundTaskExecutor.java:130) ~[?:?]
at com.liferay.portal.background.task.internal.SerialBackgroundTaskExecutor.execute(SerialBackgroundTaskExecutor.java:63) ~[?:?]
at com.liferay.portal.kernel.backgroundtask.DelegatingBackgroundTaskExecutor.execute(DelegatingBackgroundTaskExecutor.java:41) ~[portal-kernel.jar:?]
at com.liferay.portal.background.task.internal.ThreadLocalAwareBackgroundTaskExecutor.execute(ThreadLocalAwareBackgroundTaskExecutor.java:72) ~[bundleFile:?]
at com.liferay.portal.background.task.internal.messaging.BackgroundTaskMessageListener.doReceive(BackgroundTaskMessageListener.java:120) [bundleFile:?]
at com.liferay.portal.kernel.messaging.BaseMessageListener.doReceive(BaseMessageListener.java:48) [portal-kernel.jar:?]
at com.liferay.portal.kernel.messaging.BaseMessageListener.receive(BaseMessageListener.java:34) [portal-kernel.jar:?]
at com.liferay.portal.kernel.messaging.InvokerMessageListener.receive(InvokerMessageListener.java:74) [portal-kernel.jar:?]
at com.liferay.portal.messaging.internal.ParallelDestination$1.run(ParallelDestination.java:56) [bundleFile:?]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) [?:?]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) [?:?]
at java.lang.Thread.run(Thread.java:829) [?:?]

Environment

• Liferay DXP 7.4

Resolution

• The behavior you is a limitation of the "Enable custom language settings for sites with template propagation" configuration: it should not be possible to reduce the locales on the Site level compared to the system level.
• The locale list on Site level should be able to be extended only.

Additional Information

• There is a Feature Request ticket raised to disable the possibility of reducing locales on the Site level, if the Site is created from a Site Template: LPS-179885