Delta Force error 5/1200: login failed (fix)
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Last checked
September 23, 2026
Login fails with an "ID: 5/1200" message instead of reaching the main menu; several independent Steam Discussions threads report the exact same code.
Also appears as: delta force error 5/1200, delta force login failed 5/1200, delta force login failed id 5/1200, ID: 5/1200, delta force error id 5 1200
5/1200 behaves like the same family of login errors as 4/35 — a Steam Discussions post specifically titled "To fix 'Delta Force login failed 5/1200'" describes deleting the same cached session token file the launcher stores locally, and reports that fixing it. It isn't described as a server-side outage in any of the threads reporting it; treat it as a local login-cache issue first.
What to try
- 01Right-click Delta Force in Steam Library > Properties > Installed Files > Browse. Go to Launcher\Cache\TSF4G2\ and delete session.txt, then restart the game — this is the fix reported to work for this exact ID.Reported
- 02If that doesn't resolve it, run "Verify integrity of game files" from Steam's Installed Files tab to repair anything else out of place.Reported
Did this fix it for you?
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What people are saying
Notes from players who've hit this one — no time limit, an answer from months ago is still an answer. Say where you are and what you see on screen.
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- Nothing reported here yet.