"Problem with the configuration: Unknown release in folder ..." when patching the source code

Issue

• When patching the source code, customers may receive the error:
  

  "Problem with the configuration: Unknown release in folder ..."

Environment

• Liferay DXP 7.1+

Resolution

1. Have a usable ReleaseInfo.java file taken from liferay-dxp-src/portal-kernel/src/com/liferay/portal/kernel/util/ in a source code patched with a previous fix pack: to assess whether the file is "usable", check that the final lines contain actual string values instead of @@ placeholders
2. In the source, replace the liferay-dxp-src/portal-kernel/src/com/liferay/portal/kernel/util/ReleaseInfo.java file having the @@ placeholders with the one without them
3. Proceed with the normal patching operations

Additional Information

• The issue will be permanently resolved in future fix packs
• Further info: https://issues.liferay.com/browse/LPS-107524