Basic search no longer works

I have upgraded a working version of SuiteCRM where the search function worked ok. It now does not work, and cannot locate accounts for example even though you can manually locate them. Is there a way of either flushing the index or creating a new index? I am not using ElasticSearch on this system. Just the original default search which has worked fine until now. I am running version 7.14.2 Sugar Version 6.5.25 (Build 344).

Apart from ElasticSearch, there are two other ways of having search in SuiteCRM.

If you’re using AOD Search (Lucene) then start by checking if your scheduler jobs are running fine. If they are, but your index is somehow broken, you can try this: