EDIT: not every link. I can navigate around fine using this new IP/address but old links on the forum (for example written by a user in a post) don't work.
Yeah, you'll have to manually rename the link in that case. Most browser should allow you to copy the link, for example by right-clicking the link and the select a command like "copy target" in the popup menu. Then paste into address box and replace
www.lemmingsforums.net with 142.93.6.137.
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I think something might still not be set up quite correctly, as I'm still having issues accessing the site while on my workplace's computer/network, but not on my home computer/network. More interestingly, the workaround to use the IPv4 address works for my workplace computer, but not if I use the IPv6 address instead.
For reference, here are the symptoms for me at work:
At first, the forum home page loads fine and shows recent posts (so it's not like it's somehow showing an old copy of the forum from the old location), but then clicking on any link results in the error shown in attached screenshot, at which point you are stuck in that state (even if you manually go back to the home page). Restarting browser and/or clearing browser cache/history sometimes could allow the home page to load successfully again, but you still end up with the error again on next click of any link from the home page. This has never happened before on the old location.
If I ran "tracert
www.lemmingsforums.net" the output shows the IP address it resolves to, and it is the new one, so I don't think this is a case of the new location not yet propagated to DNS.
If I access the forum via IPv4 address (142.93.6.137), that works perfectly. On the other hand, if I access the forum instead via IPv6 address (eg. https://[2604:a880:400:d1::826:4001] ), the resulting experience is pretty much same the above.