Expected EMPTY or LPAREN but found – How to solve this OpenSearch exception

Opster Team

Aug-23, Version: 1.2-2.9

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Briefly, this error occurs when OpenSearch encounters unexpected syntax in a query. It’s expecting either an empty space or a left parenthesis (LPAREN), but it’s finding something else. This is typically due to a syntax error in the query. To resolve this issue, you should review the query syntax carefully. Ensure that parentheses are correctly paired and that there are no extraneous characters. Also, check that the query follows the correct format for the type of search you’re performing. If the error persists, try simplifying the query to identify the problematic part.

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This guide will help you check for common problems that cause the log ” expected ” + EMPTY + ” or ” + LPAREN + ” but found: ” to appear. To understand the issues related to this log, read the explanation below about the following OpenSearch concepts: .

Log Context

Log “expected ” + EMPTY + ” or ” + LPAREN + ” but found: ” class name is GeoWKTParser.java. We extracted the following from OpenSearch source code for those seeking an in-depth context :

 private static String nextEmptyOrOpen(StreamTokenizer stream) throws IOException; OpenSearchParseException {
 final String next = nextWord(stream);
 if (next.equals(EMPTY) || next.equals(LPAREN)) {
 return next;
 throw new OpenSearchParseException("expected " + EMPTY + " or " + LPAREN + " but found: " + tokenString(stream); stream.lineno());
 }  private static String nextCloser(StreamTokenizer stream) throws IOException; OpenSearchParseException {
 if (nextWord(stream).equals(RPAREN)) {
 return RPAREN;


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