McAfee has investigated this behavior and found that the Root Cause Analysis (RCA) has been established as an issue with Rapid Storage Technology (RST) legacy OROMs, which can affect some versions of Dell PC OEM BIOS.
 

Dell is providing (since April 20, 2015) BIOS updates on their public download pages at http://www.dell.com/.
 
NOTE: Links to the BIOS updates are included in the following Dell article SLN296627: http://www.dell.com/support/article/al/en/aldhs1/SLN296627/en?c=al&s=dhs&cs=aldhs1&l=en

For the Dell E3x50 and 3x50 models, the BIOS version A05 update resolves this issue for the following:
 

• Latitude E3550
• Latitude 3550

 
For the Dell E5x50 and 5x50 models, the BIOS version A06 update resolves this issue for the following:

For the Dell E7x5 and 7x50 models, the Dell BIOS version A03 update (apart from DELL E7350, was released on April 15, 2015 to resolve this issue for the following:

 

NOTES:  If your XPS model incurs this issue, visit the Dell download page for the latest posted BIOS update.