OTH, I can open the page pakfire.ipfire.org without any issues so can I open all other websites.
Any idea what might cause this?
On console, command pakfire status shows (last lines only):
Core-Version: 2.27-x86_64
Core-Update-Level: 167
Last update: 244d 6h 48m 2s ago
Last core-list update: 10m 58s ago
Last server-list update: 11m 1s ago
Last packages-list update: 11m ago
Core-Update available: yes (172)
Package-Updates available: 24
Reboot required: no
The pakfire.cgi code was changed significantly in CU170 to improve the operation, improve the error handling and ensure that you see the logs while the update is occurring.
Maybe the change from CU167 to CU172 is too large to smoothly encompass those changes.
As @bbitsch suggested try the upgrade command from the command line as the refresh showed in your messages that it knew there was a CU172 available.
After the update from CU169 to CU170 my pakfire logging and status display is much better and more consistent than before so once you have the cgi code properly updated it will run much better.