Still good information here, thanks for sharing guys.

The Auto Save is a builtin featured of vBulletin 4.0, i can change the interval of when it saves... think it is every 30 seconds right now. I don't think that is causing the issue though... it is something that is only effecting random users and it is related to the browser and AJAX... plus I think the cache.

Try clearing cookies, restarting your computer or a different browser yet?


I'm on Win 10, Chrome 52 and using Light theme, as well... I tested all themes' quick reply and was fine... this is so weird!

Also, I just uninstalled vbSEO (and installed DBSEO) - so there is a chance that was impacting this issue, as well - since it was very old and doees effect a lot of the core VB files. So I would reset cookies, restart computer, try a different computer, etc... Let me know if you still have problems and I'll keep digging. Sorry for the inconvenience!