Older replays (pre-May 2026) fail to parse — 100% frame rejection

[reflectionsa]

Summary

5 out of 8 .echoreplay files tested fail to parse completely. Every line is rejected. The failing files are from March and April 2026. Files recorded in May 2026 parse correctly.

Reproduction

Run nevr-anticheat against any of the failing replays:

.\nevr-ac.exe --config configs\default.toml analyze rec_2026-03-27_19-06-56.echoreplay
Error reading echoreplay: no valid frames found in replay (450 lines read, 450 rejected)

Affected files

File	Size	Lines	Result
rec_2026-03-27_19-06-56.echoreplay	2.7 MB (ZIP)	450	450 rejected
rec_2026-03-27_21-26-06.echoreplay	1.5 MB (ZIP)	804	804 rejected
rec_2026-04-30_23-27-36.echoreplay	46.4 MB (ZIP)	6476	6476 rejected
rec_2026-04-30_23-35-23.echoreplay	~0 MB (ZIP)	1	1 rejected
rec_2026-04-30_23-44-05.echoreplay	17.9 MB (not ZIP)	696	696 rejected

Working files (for comparison)

File	Size	Result
rec_2026-05-01_14-27-52.echoreplay	29.8 MB (ZIP)	153,257 frames parsed OK
rec_2026-05-01_14-58-25.echoreplay	12.6 MB (ZIP)	66,726 frames parsed OK
rec_2026-05-01_15-10-00.echoreplay	13.9 MB (ZIP)	74,242 frames parsed OK

Root cause (diagnosed)

March files (ZIP-compressed): The inner NDJSON content produces invalid character '{' after top-level value when passed to json.Unmarshal. This indicates the old format had multiple JSON objects concatenated on a single line (e.g. TIMESTAMP\t{disc_json}{teams_json}) rather than one unified session payload per line.

April raw file (rec_2026-04-30_23-44-05): Not ZIP-compressed — the parser falls through to raw NDJSON mode but still rejects all 696 lines. Unknown format difference; not investigated further.

May files (working): ZIP-compressed NDJSON, one JSON object per line with format YYYY/MM/DD HH:MM:SS.mmm\t{...}. Top-level keys include teams, disc, sessionid, game_status, etc.

Impact

All replay data collected before approximately May 2026 is unanalyzable. This includes historical abuse clips and full match recordings that may contain evidence of the players under active review.