When upgrading from Artifactory 4 to 5.0.1 or below with an existing binarystore.xml that uses the IAM Role settings for S3, which requires the <roleName> tag, the upgrade process which creates a new binarystore.xml file in $ARTIFACTORY_HOME/etc/binarystore.xml removes the <roleName> tag and causes Artifactory to fail starting up with an exception stating that "The identity field is required". It is stating this message because with no <roleName> and no <identity> field, it has no means to authenticate with S3. Below is what it should look like:
<provider id="s3" type="s3">
You can workaround this by simply adding the <roleName> tag manually, but it is not 100% clear where the error is when viewing the logs at first.