What error message does the Time Series Forecasting platform say? Is it something like in this screenshot? If so, that means your series probably has duplicated timestamps, e.g. 07/2015 appears twice or more in Customer Y's series. Even a series or more has problem, the platform should be able to analyze other series that don't have problems.
![peng_liu_0-1629512206451.png peng_liu_0-1629512206451.png](https://community.jmp.com/t5/image/serverpage/image-id/35226i14E973C769075402/image-size/medium?v=v2&px=400)
Data quality is a challenge during forecasting many series. Group Summary of Time and Group Summary of data can help to reveal difficult-to-spot issues.