Problem found when using jira bamboo plugin (possibly applicable to other screens).
Java code returns Collection but freemarker wants to treat it as a list:
BuildResultSummary.getArtifactsLinks(thatExist)
Underlying collection is not a list, it's com.google.common.collect.Collections2$FilteredCollection The problematic instruction: ---------- ==> list artifactLinkRow as artifactLink [on line 93, column 25 in fragments/plan/displayWideBuildPlansList.ftl] in user-directive showFullSummaryDetails [on line 189, column 5 in fragments/plan/displayWideBuildPlansList.ftl] in user-directive planList.showBuildResultSummary [on line 19, column 9 in fragments/buildResults/issueFocussedBuildResults.ftl] ---------- Java backtrace for programmers: ---------- freemarker.template.TemplateModelException: Underlying collection is not a list, it's com.google.common.collect.Collections2$FilteredCollection at freemarker.ext.beans.CollectionModel.get(CollectionModel.java:126) at freemarker.core.SequenceBuiltins$chunkBI$ChunkedSequence$1.get(SequenceBuiltins.java:749) at freemarker.core.IteratorBlock$Context.runLoop(IteratorBlock.java:176) at freemarker.core.Environment.visit(Environment.java:417) at freemarker.core.IteratorBlock.accept(IteratorBlock.java:102) at freemarker.core.Environment.visit(Environment.java:210)