I posted the required link from my phone which I'd connected to one of my trailhead playgrounds and then I check the challenge and it says "Challenge Not yet complete... here's what's wrong: 
Could not find a link post to Trailhead in your Chatter feed. Please check the requirements."

However, I can see the posting.  How can I complete this challenge to get the badge and points?

I posted the required link from my phone which I'd connected to one of my trailhead playgrounds and then I check the challenge and it says "Challenge Not yet complete... here's what's wrong: 
Could not find a link post to Trailhead in your Chatter feed. Please check the requirements."

However, I can see the posting.  How can I complete this challenge to get the badge and points?

Hello Everyone,

I am on the Learn CRM Essentials -> Data Quality module and am at the point where I need to install the Data.com Assessment App to complete the challenge.

I am able to install it, but when I click "Check Challenge," it gives me the error message the the package could not be found intsalled in the org.

I've tried uninstalling and reinstalling, and I've also tried going through Incognito in Chrome as the troubleshooting guidelines suggested, but nothing seems to work.

Any feedback will be greatly appreciated.

I am getting this error: "Challenge Not yet complete... here's what's wrong: 
Could not find a link post to Trailhead in your Chatter feed. Please check the requirements."

I have followed the instruction give and I am still getting this error.
 

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!