Elasticsearch error

I need advise on this issue. Please see below. A single word search finds 32 documents but when I use two words with AND between them it fails. There are documents containing both words:

Now every single search fails after I played with my MAYAN installation little bit. Tried to go back to Whoosh but it failed. Then reinstalled elasticsearch. All seems working fine but…?
I am really confused right now.
I appreciate any help.

The first error message means that each of the terms are too generic and returned more than 10000 results each.

This is an error generate by ElasticSearch and not Mayan. This is why it is prefixed with an API HTTP error 400 (Bad request). ElasticSearch is notifying Mayan that it made a request it cannot fulfill.

The second error is cause by Whoosh having a more limited lexicon support and by having an uninitialized index file.

Always execute the search backend initialization command when switching between search backends.