A package update may pause because its new configuration file differs from the version already on the computer. The local file may have been edited by a person or another setup tool. Choosing the maintainer's version without inspecting the difference can remove a setting the business relies on.

Identify what is being decided

Read the full path named by the prompt and the package being updated. Note the application or system function that uses the file. If someone else maintains this machine, keep the prompt open while they review the decision instead of guessing based on the filename.

Ubuntu's documented dpkg prompt offers a differences view, commonly selected with D. Use the actual on-screen choices. Look for changed server addresses, paths, access rules or other local settings alongside new options introduced by the package. Review sensitive values privately rather than posting the complete configuration to a public forum.

The choices commonly include keeping the current file or installing the package maintainer's version, with keeping the current version shown as the default. A default is a fallback behaviour, not proof that the old settings remain compatible with the new software.

Preserve both requirements

Ask the maintainer to preserve a copy of the relevant local configuration and decide which changes need merging. Keeping the local version may require adding a newly required option later; taking the new version may require restoring a deliberate custom setting. Document the specific choice and reason.

Some packages support separate configuration snippets in a documented .d directory. For future changes, that supported mechanism can reduce conflicts with package-managed files. Do not assume that every application reads an invented snippet directory.

Once the update has completed, validate the affected configuration using the application's documented check and test the actual feature it controls. A successful package transaction does not prove that a custom connection, path or access restriction survived. Retain the comparison until that functional check has passed.

Sources: Ubuntu documentation, Ubuntu documentation.