Unable to create collection MyCollection.
Unable to create Solr collection MyCollection.
An error occurred while creating the collection: org.apache.solr.common.SolrException. Check the Solr logs for more detail.
To fix this issue you need to ensure your collection directory has the correct permissions. Under Windows ensure your user has full access. With Linux make sure that the same user as your ColdFusion service runs under. For example root/nobody etc.
To change a folders user:group in Linux CentOS you can use this command:
chown -R root:root /home/MyCollection
The above code will recursively change all folders/files to be used under root