Who can help me?
It is displayed because it is informative feedback. It tells you that your Axure program is not able to connect to the Axure Share server.
If your internet connection works in general, then the site may be temporarily down, or is blocked by your internet service provider, hotspot, company or government. If you have an internet connection, you can try to load share.axure.com in your web browser (or whatever URL might be valid for your country/locale) to test the general Axure Share site. If that loads, then try closing Axure and restarting the program, then try posting or connecting again. I’ve noticed that sometimes (rarely) if my IP address changes, Axure won’t connect up to Axure Share until I restart it. For example, I start in Axure at my work office, put my computer to sleep, go home and resume working, and can’t check in/check out pages until I restart the program, then it works fine.
If the problem persists, contact email@example.com and they can help you out, I’m sure.
To add on to mbc66’s answer, if you find that you’re able to load <share.axure.com> in the browser but Axure RP won’t publish to Axure Share, then you’ll want to check any security tools, proxies, and firewalls on your end to make sure that Axure RP’s access to the internet and to Axure Share is not being interrupted. The connection troubleshooting guide can help you through what to check.
If you still run into issues after trying the steps in the troubleshooting guide, then as mentioned above please go ahead and email us at firstname.lastname@example.org with details about your OS along with the steps that you’ve tried so that we can assist. Thank you!