When it happens
Phrase filters (mark_text_phrase, owner_name_phrase, representative_name_phrase) use full-text indexes. An index is served only while it exists and passes a health check; during a rebuild, or if the check fails, requests that need it get this error.
What to do
Retry later. Meanwhile, exact filters (mark_text, numbers, *_key) and all other filters keep working.
Example
Headers
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