MathCAD Prime - MC 15 License error

[BD]

I'm getting an error on requesting free license when installing Mathcad 15, after just installing Mathcad Prime.   I'm using windows 10.  When acquiring the license in the last step a box pops up-Unexpected error

The server committed a protocol violation.

Section=ResponseHeader Detail=CR must be followed by LF.

[VladimirN]

Open a new case by using "Mathcad Installation & Licensing Support Center": https://support.ptc.com/support/mathcad_supportCenter.htm

[Fred_Kohlhepp]

Have you tried pointing 15 at the Prime license?  The same license works for both.

Spoiler

[VladimirN]

"Error "The server committed a protocol violation. Section=ResponseHeader Detail=CR must be ......"": https://community.ptc.com/t5/PTC-Mathcad-Installation/Error-quot-The-server-committed-a-protocol-violation-Section/td-p/706423