Note: If necessary, delete an existing greeting (limit of 2 greetings) to make room for the new greeting: Tap the Menu key, tap Delete greetings, tap the check box next to the desired greeting, and then tap Delete. Tap the Record icon to record your greeting. Tap the Stop recording icon to stop recording.
If you are unable to set up your voicemail through phone settings, then you can try setting it up through your carrier. Voicemail is related to your carrier and it is best to be done this way. This may not work for all kind of carriers. You can easily apply this method by following the steps below:

We managed to discover some of the most common causes that will trigger this particular issue. We have done this by looking at various user reports and the repair strategies that they used to get the issue resolved. Here is a shortlist with common scenarios that have the chance of triggering this particular error message:
Salespeople who call and hang up screen themselves out of the process. No matter if you're prepared to leave the perfect voicemail or not, you need to leave one every time. However, if you do record a few messages with the same ultra-specific question, the prospect feels a twinge of guilt each time you call back because they feel they owe you an answer.