Approved I-140 Withdrawal notice after 3.5+ years of permanent residency

[G00dhealth]

Approved I 140 Withdrawal notice after 3.5+ years of permanent residency, What are my options and next steps?

I applied for Green card through my previous employer A with I140 and I485 concurrent filing in April 2014. My application was processed and I got my green card in Oct 2014. I changed to a new employer B nine months back in Aug 2017. 

In May 2018, 44 months from the date I got my green card, I got a ### notice acknowledging withdrawal of this application or petition I140 IMMIGRANT PETITION FOR ALIEN WORKER### from USCIS. 

1. What does this withdrawal mean, I already have permanent residency? 

2. What is the difference between withdrawal and revokation? 

3. What impact it has on my permanent residency? 

4. Does it impact my current employment with employer B? 

5. What options do I have and what steps I need to take? Should I check with previous employer? or inform USCIS that I have received Green Card?

[pontevecchio]

Discuss the facts with the firm of Murthy or any of your choice. How were you even monitoring the status? This is a clerical error and you will be fine.

[JoeF]

That looks very strange. I second pontevecchio's suggestion.