ClassCastException during upgrade when setting maximum file size using config file

Issue

• During the upgrade process from Liferay DXP 7.2 to 2025.Q1, a ClassCastException occurs when setting the maximum file size using the OSGi configuration file com.liferay.document.library.configuration.DLConfiguration.config. The error message indicates that a string value cannot be cast to a long value, specifically for the fileMaxSize property:

  2025-04-23 18:16:43.737 ERROR [main][UpgradeExecutor:333] Failed upgrade process for module com.liferay.document.library.service com.liferay.portal.kernel.upgrade.UpgradeException: java.lang.ClassCastException: class java.lang.String cannot be cast to class java.lang.Long (java.lang.String and java.lang.Long are in module java.base of loader 'bootstrap')
  

Environment

• Liferay DXP 7.2
• Liferay DXP 2025.Q1 (Quarterly Release)
• MySQL

Resolution

• This issue appears related to changes in LPS-125016 and LPS-135504. To resolve this, set the maximum file size through the Control Panel instead of using the configuration file. Go to Control Panel > System Settings > Documents and Media and update the value there. This method ensures the value is stored correctly in the database, allowing the upgrade to proceed without errors. The updated maximum file size will then be correctly reflected in the upgraded 2025.Q1 system.