That version is more than two years old, so you could update your software to a recent version, but it should still work. You can try to kill any afni and suma processes on that computer with "killall afni" and "killall suma". You can specify port block numbers when you start afni and suma to be sure they are on the same unused port block.
set PIF = "DriveAfniSuma"
set NPB = "-npb `afni -available_npb_quiet` -pif $PIF"
@Quiet_Talkers -pif $PIF #Quiet previously launched programs
afni $NPB -niml -yesplugouts
sleep 2
suma $NPB
Make sure the afni GUI shows the NIML+PO box grayed out or click it to turn on the communication. You can also try driving suma and afni separately with DriveSuma to drive suma and plugout_drive to drive afni (which doesn't use the niml format). For example, if suma is "talking", then this should show some text in the upper left corner of the suma window:
DriveSuma -com viewer_cont -fixed_do "<T text='Up here' p=tlf/>"
Your local security software administration may have imposed a firewall. While it's not usually required, you can try to allow the afni and suma applications to accept incoming network connections when you first start these applications. A message appears like this:
Do you want the application "afni" to accept incoming network connections?
Clicking Deny may limit the application's behavior.
This setting can be changed in the Firewall pane of Security and Preferences.
Deny Allow
Click Allow.
You can check if an application is allowed or denied in that Preferences panel, Security & Privacy, Firewall tab.
Click the lock to allow changes. Click Firewall Options. In the list, make sure afni and suma are listed. If not, you can add them with the '+'.