Hi,
I see the same issue on an SRX running 12.1X46-D86. After upgrade, J-web login fails,while SSH works fine. J-Web shows the following message- Invalid username or password specified - both for root as well as non-root user login attempts.
May 18 10:21:19 SRX checklogin[1806]: warning: can't get client address: Bad file descriptor
May 18 10:21:19 SRX checklogin[1806]: WEB_AUTH_FAIL: Unable to authenticate httpd client (username root)
May 18 10:21:35 SRX checklogin[1810]: warning: can't get client address: Bad file descriptor
May 18 10:21:35 SRX checklogin[1810]: WEB_AUTH_FAIL: Unable to authenticate httpd client (username pradeep)
May 18 10:22:08 SRX sshd[1813]: unlink(): failed to delete .perm file: No such file or directory
May 18 10:22:08 SRX sshd[1811]: Accepted keyboard-interactive/pam for pradeep from 10.10.10.1 port 54074 ssh2
May 18 10:22:11 SRX mgd[1816]: UI_AUTH_EVENT: Authenticated user 'pradeep' at permission level 'j-operator'
Seems to be an issue with this particular Junos version. Will update this thread later, if there is any fix.