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I obtain this error when I try to access to category but the google console don't give me some details but only that the error is:
"Cannot read property 'locked' of null"

nodebb.min.js:25243 Uncaught TypeError: Cannot read property

at this line:
helpers.generateTopicClass = function(topic) {
var style = [];
//at this line
if (topic.locked) {
style.push('locked');
}

if (topic.pinned) { style.push('pinned'); } if (topic.deleted) { style.push('deleted'); } if (topic.unread) { style.push('unread'); } return style.join(' '); };

I think is for the async.waterfall call because
function(data,callback){
async.waterfall([
function(next){
//someOperation
next(null,topic);

}],function(err,topic){
data.category.topics = topic.concat(data.category.topics);
});

Anyone can help me?