Interesting! How very odd. To confirm, are all three of you on Axure RP 8 build 3382, and does the preview fail in all files and not just one specific file?
It looks like some of you are on Mac and some on Windows, and preview fails in each browser. Axure RP 8 build 3382 is stable and has been out for quite a while; to verify, did you all already have that build installed and working normally before the preview issue happened, or did you recently update to that build?
If there was no Axure RP update when the problem started and IT has verified that there were no proxy/security changes that would impact Axure RP’s ability to connect to localhost, then were there any OS or browser updates at around the same time that each of you started noticing the issue? Similarly, were there any automatic updates to browser extensions that you have installed in each of your browsers, or perhaps to any security tools/antivirus software on your machines?
Additionally, if you’re able to send over a screenshot of what you see in the browser developer console when the preview fails then we can check to see if there are any clear errors. You can grab that screenshot by right-clicking the browser page, choosing “Inspect” to open the developer tools window, and then clicking the “Console” tab in the window that opens and taking a screenshot (errors are usually in red).
To supplement the “Console” tab screenshot, please also save a copy of the HAR file and send it our way. To get that HAR file, click on the “Network” tab in the developer tools window and start capturing network traffic; in Chrome you would do this by enabling the “Preserve logs” checkbox. Once capturing has started, please refresh the preview page that failed to load, which should cause the “Network” tab to fill with data. In the left-hand column of the “Network” tab you should see “start.html” listed; please right-click that and choose “Save as HAR with content” to export the HAR file.
Please send both the screenshot and HAR file over to firstname.lastname@example.org and reference this thread so that we can take a look and better diagnose what’s causing the preview issues for each of you. Thank you!