EL syntax error: Expecting Expression on EL string concat operator ------------------------------------------------------------------ Key: JBIDE-23891 URL: https://issues.redhat.com/browse/JBIDE-23891 Project: Tools (JBoss Tools) Issue Type: Bug Components: jsf Affects Versions: 4.4.2.Final Environment: Windows 10 Eclipse Neon.2 (4.6.2) JBoss Tools 4.4.2.Final (Marketplace) JavaEE 7 Reporter: Tran Minh Do Priority: Minor Fix For: 4.15.x The EL 3.0 specification [1] states String Concatenation Operator - A += B To evaluate A += B ■ Coerce A and B to String. ■ Return the concatenated string of A and B. Used on a JSF Tag like {code:java} <h:outputText value="#{'foo' += 'bar'}" /> {code} leads to following warning: *EL syntax error: Expecting expression.* on the *=* part of the *+=* operator. [1] http://download.oracle.com/otn-pub/jcp/el-3_0-fr-eval-spec/EL3.0.FR.pdf