Reference Index

Maybe the upgrade of the reference index isn't run proper.

Probably the cause are "broken" links: the internal syntax of TYPO3 for links is changed.

The manual of the Organiser (EXT:org) provides some SQL statements for analysing trouble with the link syntax.

Please refer to

• https://docs.typo3.org/typo3cms/extensions/org/

Look for

• Upgrades > TYPO3 7.6 > 8.7 > Extensions > Linkhandler