You're supposed to create a link post in chatter.  Did it but it doesn't work.  Other posts says others are having the same problem. 

You're supposed to create a link post in chatter.  Did it but it doesn't work.  Other posts says others are having the same problem. 

I'm trying to complete the chatter section on Trailhead, and I'm getting the error "Challenge Not yet complete... here's what's wrong: 
No feed post was found that linked to the Trailhead URL.", and this doesn't make sense because I clearly posted the URL multiple times.

The criteria: Using the standard poll and link Chatter actions, create two posts to engage with the Chatter user community.
Create a poll post. Ask your users to rate their experience with Chatter and ask for feedback in comments.
Create a link post. Share a link with other users to http://developer.salesforce.com/trailhead - the best learning tool for Salesforce out there!