Hello, there has been issues with the Buffer and Multiple Ring Buffer tools failing if they had the 'Dissolve All' option specified. Those issues were reported as bugs and the workaround consists of using those tools without the 'Dissolve All' option set > and then using the Dissolve tool separately from ArcToolbox.
Is this issue that you are running into with the 'Dissolve All' option set?
Thanks so much for your response. Yes, I tried running Multiple Ring Buffer again without the 'Dissolve All' option checked and the process did execute, but there is still a problem. Although the output layer shows two buffer distances (.25 and .5), in the attribute table there is only one distance listed (.5). So I don't think I can use the 'Dissolve' tool to fix my problem because I do not have a field to base the process on. I have attached a photo of the attribute table and screen... any ideas of what to do?