Sounds plausible, but why having the issue also in other topic of the last (at least 5) registrations when wishing to post in there topics, or resave a topic of them?
Posting in a topic is not a problem, as far as I could see.
Resaving the welcome post could cause the problem when the "@..." is still in it. Same with quoting, if the "@..." is still in the quoted text.
There are several different welcome texts. In some of them, the problem does not occur. If I see correctly, then the problem only occurs if (the user has letters like 'ä' in their name or ...) the Khmer text follows the @..., without any
[ tags ] in between, which clearly separate the name (things like comma, space and even new line are not interpreted as separators for the script trying to expand the name). As soon as a special character is interpreted as possibly belonging to a name, performing a database query with it, it would cause the error.
And why the error when activating accounts, Nyom Moritz ?
I don't know what other error there was?
I think it has not been made clear.
Maybe Atma had the issue only in welcome topics... At least the text of the welcome topics works like that since moee then a half year, so maybe a combination of small old errors in regard of utf-8 (smf-bug) and issue there because of different database not compensaring them, bringing the bug to be seen.
Yes, I think it all worked well before. So something must be wrong in the new database.