Reply in the thread with the exact change that solved the problem and the result you observed. Mention the relevant setting, tool, or input condition. If a suggested step did not help, include it only when it prevents another reader from taking the same wrong path.
For example: “Quoting the CSV field containing commas fixed the import; three sample rows now produce the expected columns.” That is more useful than “fixed, thanks.” If the solution is temporary or only works in one environment, say so. Keep account details and private files out of the follow-up.
A clear ending turns the discussion into a searchable answer.
Akousa