On the machines that your trying to access the Performance Center web client in IE 11, ensure:

* ALM URL is added to the ''Trusted Sites'' in IE's internet options
? In Internet Explorer, select Tools > Internet Options. The Internet Options dialog box opens
? In the Security tab, select Trusted Sites, and click Sites
? If you are not using SSL, ensure that the Require Server verification (https:) for all sites in this zone option is not selected
? In the Add this website to the zone box, enter the Performance Center Server internal URL (http://[ALM server name]:8080/qcbin), and click Add

* Set Compatibility View correctly in IE 11

A. Close all instances of IE
B. Open IE
C. Navigate to the IE ''Tools''
D. Select ''Compatibility View settings''
E. Add the ALM Server
F. Add the PC Server
G. Uncheck ''Display intranet sites in Compatibility View''
H. Close the ''Compatibility View settings'' dialog box
I. Close IE

In addition, Micro Focus states the following in the System Requirements for 12.60:

''For optimal performance on Windows, We recommend using Google Chrome.
** When using Microsoft Internet Explorer, We recommend opening a new browser window/session.''
I hope this helps.