Request popular posts via REST API causes an error

[Sebastian Böttger]

According to API documentation, it is possible to request the REST API to get popular posts (Have a look here), but an error happens.

Can't handle request for param object: org.bibsonomy.database.params.BibTexParam@34ed68c5[ ratingAverage=arithmetic_mean 
resource=<null>
relation=<null>
tags=<null>
tag=<null>
tagName=<null>
title=<null>
author=<null>
tagIndex=[]
numTransitiveConcepts=0
numSimpleConcepts=0
numSimpleTags=0
numSimpleConceptsWithParent=0
numSimpleConceptsWithAncestors=0 numCorrelatedConcepts=0
groups=[254, 0, 292]
groupNames=[group_292, group_254, public]
relationTagIndex=[]
relationTags=[]
caseSensitiveTagNames=false
date=<null>
changeDate=<null>
requestedContentId=0
hash=<null>
simHash=SIM_HASH
search=<null>
searchType=LOCAL
rawSearch=<null>
userName=seboettg
description=<null>
extension=<null>
requestedUserName=<null>
groupId=-1
requestedGroupName=<null>
startDate=<null>
endDate=<null>
limit=20
offset=0
idsType=IDS_UNDEFINED_CONTENT_ID
newContentId=0 url=<null>
contentType=<null>
order=POPULAR
grouping=ALL
filter=<null>
postAccess=POST_ONLY
days=-1
bibtexKey=<null>
systemTags=[]
approved=false ]