When upgrading to 4D v11 SQL Release 2 (11.2) any pre-existing Keyword indexes must be dropped and rebuilt. This can be done by going into the Structure Editor and manually removing the index, then reassigning it. If you would like to rebuild all your indexes you can move the .INDY and .INDX files to the trash while your database is closed, and the next time it is opened 4D will automatically rebuild the indexes.

The rebuild is necessary because with the release of 4D v11 SQL Release 2 (11.2) the Keyword index has changed slightly. The change is mostly transparent to the developer and deals with the algorithm used to separate the keywords of a Text field. In 4D v11 SQL's original release and in Release 1 a proprietary algorithm developed by 4D Engineering was used to separate the keywords in a Text field. With the new release the guidelines set by ICU for boundary analysis are used. For more information on those guidelines check the ICU website:

https://www.icu-project.org/userguide/boundaryAnalysis.html