Field Notice: FN - 64276 - Cisco Secure Access Control System 5.8 Not Able to Launch GUI with Firefox Version 52-Software Upgrade Required
There is a known problem with ACS 5.8 + Patch 4/5/6 with the upcoming Firefox 52 release which should be posted on March 7, 2017.
An ACS 5.8 administrator will not able to launch the ACS Login GUI with the Firefox version 52 browser.
Customers are advised to simply upgrade to ACS 5.8 Patch#7 before using Firefox 52 or follow the Workaround instructions in the field notice.