Well, TFS might be buggy in old clients because it doesn't support all new stuff that is in TFS. Client crashes can happen frequently if you do not change what's compatible with the client (like effects on spells). You need to adjust this yourself if you encounter any bugs if you're using TFS (if you wanna play with regular tibia client so to say). I've done this myself on my upcoming Pvp-Wow server so old tibia client will work, in this case 7.72, since that is closest to 7.6 that is supported within TFS. But I believe it's mainly the spell effects that cause crashes, I don't remember fully since I began in 2023 then took a 2 year break from it.
Take a look here if you can download any, I haven't tried myself. It was the site I used to download servers back in the days, not sure if it works with the archive link, but give it a try. I suggest doing a virus scan before downloading anything though, just in case.
Did you always wanted to make your own Open Tibia server? Well here are all the resources u need! I have got a forums, Maps, Monsters, Runes, Servers, Spells, Clients, Tools, Tutorials, Wands, a shoutbox and even more!
web.archive.org