Add to Certificate List Issue-STRUSTSSO2

Dear Techies!

I have configured the single sign-on thru Digital Certificate

Authentication for SAP WEB Gui in my ECC System.

In t-Code STRUSTSSO2, I have added almost 274 users in Certificate list,

the systems is working fine, but as soon as I add one more useru2019s

Certificate in Certificate list, System failed to open the SAP Web Gui.

I have verified that adding a certificate in certificate list is

creating the problem, when I removed that last added certificate, the

system again start working fine. (As per my findings, the issue is with

the No of certificates already being added , not with any particular

certificate)

Pls. advice, is there any restriction in adding the users in certificate

List?

Regards

Saqib