What errors have you encountered when updating Bitrix?

When updating Bitrix, the following errors are often encountered:

• Conflicts with custom modules and core modifications. If changes have been made to standard files, the update may overwrite them or cause errors.
• Compatibility issues with PHP versions. Newer versions of Bitrix may require more recent PHP versions.
• Database migration errors — sometimes the update fails due to incorrect changes in the database structure.
• File and folder permission issues — the update may not apply if the necessary permissions are not set.
• Caching — after updating, it is essential to clear the cache, otherwise old data may be displayed.

It is recommended to make backups and test the update on a site copy before proceeding.