Demo file is incompatible with this game version: the CS2 fix

CS2 shows this message when it will not replay a recording made on a different game version. The file is usually not damaged.

Open the file in a text editor. If the first line starts with PBDEMS2, it is a CS2 demo from another build: try it in a browser demo viewer, which does not run a game build. If it starts with HL2DEMO, it is a CS:GO demo and no CS2 tool will play it.

It means the game refused to replay the file, not that the file is broken. CS2 plays a demo by running it through the installed game. When the recording and the game version disagree, CS2 stops instead of guessing.

Two situations cause it:

• A CS2 demo from another build. CS2 updates change how playback works. Valve's own release notes show this: on 13 December 2023 and 8 February 2024 it "fixed an issue" that "prevented some older demos from playing back".
• A CS:GO demo. Counter-Strike: Global Offensive recordings are a different format. CS2 cannot play them at all.

By the first eight bytes of the file. A Counter-Strike 2 demo begins with PBDEMS2 and a legacy CS:GO demo begins with HL2DEMO. Both use the same .dem extension, which is why they get mixed up.

You do not need special tools. Open the file in any text editor and read the first line. Memorin checks the same bytes on upload and names the problem: a CS:GO file gets a "legacy CS:GO (Source 1) demo" message, not a vague error.

Because Valve turns it off. TrueView is CS2's playback mode that replays the match closer to what the player saw. Valve's release notes for 4 November 2025 say it "might not work properly on old demos and is disabled by default if the playback client version does not match the client version when the demo was recorded".

The same notes give the override: set cl_demo_predict 2 in the console. Valve's warning still applies, so the result may not be right on an old demo.

Valve has not published an explanation of "failed to parse message" or "invalid pbuffer", so this page does not guess at one. Both say the game could not read part of the file. Work through the same checks: confirm the header says PBDEMS2, download the demo again in case the file is cut off, and try it in a browser viewer that does not run a game build.

That is a different problem with its own fix. See CS2 demo download incomplete. In short: copy the match sharing code and let a browser viewer fetch the demo, which also tells you when the recording is gone.

Refused as "not a demo"? Check three things. Is it still inside a .zip or .rar? Unpack it first. Compressed demo streams are fine as they are: .dem.gz, .dem.zst and .dem.bz2 all upload directly. Is it only a few kilobytes? Then it is an error page saved with the wrong name.

What does demo file is incompatible with this game version mean?

It means the game refused to replay the recording, not that the file is damaged. Either it is a CS2 demo from a different game build, or it is a legacy CS:GO demo, which CS2 cannot play at all.

How do I fix demo file is incompatible with this game version?

Open the file in a text editor. If it starts with PBDEMS2 it is a CS2 demo: open it in a browser demo viewer, which reads the data without a game build. If it starts with HL2DEMO it is a CS:GO demo and no CS2 tool will play it.

How do I tell a CS2 demo from a legacy CSGO demo?

By the first eight bytes of the file. A Counter-Strike 2 demo begins with PBDEMS2 and a legacy CS:GO demo begins with HL2DEMO. Both use the same .dem extension, which is why they get mixed up.

Can a browser demo viewer open a demo the game client refuses?

It is worth trying if it is a CS2 demo. The server reads the recorded data directly and the browser draws the match, so no game build is involved. A CS:GO demo is a different format and is refused. The map must be one of the ten supported maps.

Why does TrueView not work on an older CS2 demo?

Valve disables it by default when the playback client version does not match the version that recorded the demo, and says it might not work properly on old demos. Setting cl_demo_predict 2 overrides this.

What does failed to parse message mean on a CS2 demo?

Valve has not published an explanation. It says the game could not read part of the file. Confirm the header says PBDEMS2, download the demo again in case it is cut off, and try a browser viewer that does not run a game build.

Why does my CS2 demo say download incomplete?

The game could not fetch the whole replay file. Copy the match sharing code and paste it into a browser viewer, which fetches the demo on a server and tells you if the recording no longer exists.