Error on line 27, column 51 in project.fhtml
Expecting a string, date or number here, Expression project.attributes.collaborators is instead a freemarker.template.SimpleSequence
The problematic instruction:
----------
==> ${project.attributes.collaborators} [on line 27, column 49 in project.fhtml]
----------

Java backtrace for programmers:
----------
freemarker.core.NonStringException: Error on line 27, column 51 in project.fhtml
Expecting a string, date or number here, Expression project.attributes.collaborators is instead a freemarker.template.SimpleSequence
	at freemarker.core.Expression.getStringValue(Expression.java:126)
	at freemarker.core.Expression.getStringValue(Expression.java:93)
	at freemarker.core.DollarVariable.accept(DollarVariable.java:76)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.ConditionalBlock.accept(ConditionalBlock.java:79)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.Environment.process(Environment.java:176)
	at freemarker.template.Template.process(Template.java:231)
	at com.pagesociety.web.template.FreemarkerRenderer.render(FreemarkerRenderer.java:67)
	at com.pagesociety.web.template.FreemarkerRenderer.render(FreemarkerRenderer.java:55)
	at com.pagesociety.web.gateway.FreemarkerGateway.doService(FreemarkerGateway.java:63)
	at com.pagesociety.web.gateway.HttpRequestRouter.doService(HttpRequestRouter.java:285)
	at com.pagesociety.web.gateway.HttpRequestRouter.doGet(HttpRequestRouter.java:122)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
	at com.pagesociety.web.gateway.HttpRequestRouter.doService(HttpRequestRouter.java:276)
	at com.pagesociety.web.gateway.HttpRequestRouter.doGet(HttpRequestRouter.java:122)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
	at java.lang.Thread.run(Thread.java:636)