ConcurrentModificationException when searching for a keyword and an Admin user is in the author list

Caused by: java.util.ConcurrentModificationException
	at java.base/java.util.HashMap$HashIterator.nextNode(HashMap.java:1493)
	at java.base/java.util.HashMap$KeyIterator.next(HashMap.java:1516)
	at org.apache.velocity.runtime.directive.Foreach.render(Foreach.java:393)
	at org.apache.velocity.runtime.parser.node.ASTDirective.render(ASTDirective.java:207)
	at org.apache.velocity.runtime.parser.node.ASTBlock.render(ASTBlock.java:72)
	at org.apache.velocity.runtime.parser.node.ASTIfStatement.render(ASTIfStatement.java:87)
	at org.apache.velocity.runtime.parser.node.SimpleNode.render(SimpleNode.java:342)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluateInternal(DefaultVelocityEngine.java:259)
	at org.xwiki.velocity.internal.DefaultVelocityEngine.evaluate(DefaultVelocityEngine.java:222)
	... 187 more