I recently upgraded my site to a more recent 2.6 release. I was on 2.6 anyway and everything had been fine. I went to one of my courses and noticed that is was not in the right format, went to change to Collapsed Topics and found no option. Thinking that I must have missed adding that back in on the last upgrade, I went to install through the web interface and downloaded the latest version. Moodle is telling me that I have a newer version installed and will not let me "downgrade" so I had to delete the topcoll folder out of course formats - it is telling that the version I have installed is from 12/18 but the version being reported on the latest download is 11/18. Was there a newer version at some point that got pulled out?
No, there was no newer version that got pulled. You must be looking at a cached screen or something as the latest version is 12/18 - being 126.96.36.199 (2013121800) on https://moodle.org/plugins/pluginversions.php?plugin=format_topcoll.
Please double check that your internet access is not caching the connection / lost to the plugin's DB when installing through the web interface.
Thanks Gareth - that pointed me in the right direction - I ended up manually uploading the zip file and then it went through just fine.