Fine-tuning and troubleshooting

Solutions to the problems people actually run into.

Start here

Nine times out of ten the answer is in this table. Find the symptom, follow the link.

Nothing is being cut

The program is running, the log ticks along, and the counters stay at zero. Work through these in order — they are listed by how often they turn out to be the cause.

1. Is the External ID right?

Look at the Activity Log. If it repeatedly says:

Finished contests: 0

while fights are clearly finishing on the mats, then JudoNet is answering — it is just answering "I have no contests for that competition".

That means the External ID does not match the competition JudoNet is running. Stop cutting, click the magnifying glass next to JudoNet IP, re-select the server, and let the External ID be filled in for you.

If that does not help, check JudoNet itself: it must be running, Store Locally must be on, and the contests must actually be finished. See the CutterV2 finds no contests.

2. Is a contest filter blocking everything?

Look at the Contest Filters summary on the Automatic cutting tab. If it says anything other than No contest filters configured, a leftover filter from a previous event may be excluding this one.

Stop cutting, open the Contests tab, and clear the Included and Excluded lists.

3. Are the scene keys on the FR Recorder correct?

The CutterV2 only accepts a recording whose scene key is exactly mat followed by the mat number: mat1, mat2, mat3.

Mat 1, MAT1, tatami1 and M1 all fail to match, and they fail silently — the log reports recordings and contests, but no jobs are ever queued.

Check in FR Recorder, under Angles and scenes, that every scene key follows the mat<number> pattern, and that each stream is assigned to the right one.

4. Are the contests actually finished?

The CutterV2 only cuts contests JudoNet has marked finished, which it does a short while after the winner or no-winner screen appears. Two things follow:

• Clips lag behind reality by roughly half a minute to a minute. That is normal.
• If the scoreboard operator never displays the winner screen, the contest is never finished and never cut. Look at the Status column on the Contests tab: anything still showing In Progress will not be cut.

5. Do the recordings actually cover the fights?

A recording is only used if it started before the clip should start and was still running after the fight ended. A camera that was started late, or stopped for a break, leaves a hole.

Check the recordings list in FR Recorder against the times of the missing fights.

6. Is the camera angle filter too narrow?

If the Camera Angles box is filled in, only those exact camera keys are cut. A typo or a renamed angle means nothing matches. Empty the box to cut every angle.

7. Is JudoNet up to date?

The CutterV2 and JudoNet are developed together, and the CutterV2 relies on information that only current versions of JudoNet send. An old JudoNet does not report an error — it just supplies less than the CutterV2 expects.

Suspect this if the competition identifier does not fill in by itself when you select the JudoNet server, or if the Judoka 1, Judoka 2 and Category columns on the Contests tab are empty. Update JudoNet — and FR Recorder — to the latest version. See Keep the other programs up to date.

Only some contests are cut

"Start time exceeds end time"

The Activity Log shows a line like:

CHECK CONTEST cont_cup_jun_mac2026_0007_m_p100_0009 - Start time exceeds end time.

The CutterV2 calculated a start point that is after the contest's finish time, which is impossible, so it skipped the contest rather than producing nonsense.

This always means the scoreboard timings for that one contest are inconsistent — usually because the operator pressed something out of order, or a contest was restarted and the old marks were left behind.

Fix: cut that contest by hand on the Manual cutting tab. There is nothing to configure; the data for that contest is simply wrong.

"Recording is missing"

The Activity Log shows a line like:

Recording is missing for cont_cup_jun_mac2026_0007_m_p100_0009 Front.

The CutterV2 matched a contest to a recording, but could not reach the file — neither on a local path nor on the network share.

Usual causes:

• The FR Recorder was switched off or restarted, so the share is no longer mounted.
• The recording was deleted from the FR Recorder while its entry still exists.
• The network connection dropped.

Fix: run Test cutting to re-establish the connections, then press Retry error cuts.

Some cameras are cut, others are not

Check the Camera Angles box. If it is empty, check that the missing camera's recordings actually exist for that mat and cover the right time range.

Clips are cut at the wrong moment

Every clip is off by the same amount, in the same direction

This is a clock problem, not a settings problem: two PCs disagree about what time it is.

The proper fix is to synchronise the clocks of the JudoNet PC, the FR Recorder PC(s) and the CutterV2 PC. The installer opens the time synchronisation port for exactly this reason.

If a competition is already under way and you cannot restart anything, there are two emergency workarounds on the Settings tab:

Measure before you adjust: cut one contest, watch it, note how many seconds out it is and in which direction. Then apply the correction and cut another one to confirm.

Clips have too much or too little build-up

That is not a fault; it is the Cutting Start Mode setting.

Clips start a fraction of a second early

Expected and harmless. The internal cutting engine has to begin at a keyframe, so it moves backwards to the nearest one. See the two cutting engines.

Clips are cut short at the end

The clip ends when JudoNet says the contest finished. If the ippon and the bows are being cut off, the scoreboard is moving to the winner screen very quickly.

There is no setting for the end of a clip. If it is a recurring problem at your event, raise it with whoever configures JudoNet — the delay before a contest is marked finished is configured there, not in the CutterV2.

No servers appear in the discovery window

You click the magnifying glass and the list is empty.

The discovery windows show only servers that have announced themselves in the last few seconds. An entry that goes quiet is dropped. So an empty list means the announcements are not arriving.

Check, in this order:

1. Is the other program running? JudoNet or FR Recorder must actually be open, with a competition or session loaded.
2. Are both machines on the same network? Not just "both have internet" — the same local network, without a guest network or VLAN between them.
3. Was the Windows firewall prompt refused? If someone clicked Cancel on the firewall dialog the first time the CutterV2 started, the announcements are being blocked. Open Windows Defender Firewall → Allow an app, find the CutterV2, and tick both Private and Public.
4. Is multicast blocked? Many managed switches and most guest Wi-Fi networks drop multicast traffic. This is the usual cause when everything else looks fine.
5. Are the ports right? JudoNet on UDP 8888, FR Recorder on UDP 18918, both on multicast group 239.225.89.212. Check the Settings tab against the other program's configuration.

Error 500 when cutting from FR Recorder

A 500 Internal Server Error from an FR Recorder usually means its database holds old or invalid recordings that it can no longer describe. Confirm it first, then fix it.

Step 1 — check network access

Try to open the shared folder on the FR Recorder machine. In Windows Explorer (or Total Commander), type:

\\<FR Recorder address>\

If you are asked for credentials, see Checking the FR Recorder shared folder by hand.

If you can open the share, go on to step 2. If you cannot, the problem is network or credentials, not the database.

Step 2 — test the API

Open a browser on the CutterV2 PC and visit:

http://<FR Recorder address>:9696/api/ping

If that answers, try:

http://<FR Recorder address>:9696/api/recordings

An error here confirms that invalid recordings are the problem.

Step 3 — delete the old sessions

In FR Recorder:

1. Click Switch Session.
2. Delete old sessions, oldest first.
3. After each deletion, reload /api/recordings in the browser.
4. Once it answers cleanly, the CutterV2 will work again.

Cuts keep failing with errors

First: just retry

Click Retry error cuts. Most failures are momentary — a share that dropped for a second, a file locked at the wrong instant — and succeed on the second attempt.

Double-click the ERRORS card to copy the list of failed contests to your clipboard if you need to report them.

If the same contests keep failing

Clips rejected for being the wrong length

After every cut made with the internal engine, the CutterV2 measures the file and compares it with the length it expected. A difference of more than 2 seconds is treated as an error and the clip is not published.

This is deliberate: a truncated clip that looks fine in the file list is worse than a missing one, because nobody notices it until a coach complains.

It usually means the source recording is incomplete or damaged over that time range — often because the recorder briefly lost its input. Check the recording in FR Recorder, and cut the contest by hand if the footage is actually there.

Automatic cutting stopped because of low disk space

A dialog appears listing the output directory, the drive, the free space, the total size and the free ratio, and cutting stops.

The CutterV2 requires at least 5 % free space on the output drive. Below that it refuses to continue, because a drive that fills up mid-clip produces truncated files and Windows itself starts misbehaving.

What to do:

1. Make room — move already-uploaded clips off the drive, or empty the recycle bin.
2. Confirm with the Video Ingester that the clips you are deleting have actually been uploaded.
3. Press Start cutting again. The CutterV2 re-reads the folder, works out what is missing and catches up.

The check also fires if the drive becomes unavailable — a disconnected USB disk or a dropped network drive. The message then names the reason instead of the free space.

Cannot connect to JudoNet

A dialog says "Cannot connect to JudoNet API!" with an error and a URL, and cutting stops.

The CutterV2 tolerates a single missed poll; it stops only after two consecutive failures, about 40 seconds. Pop-ups are limited to one every two minutes so a network outage cannot bury the screen in dialogs.

"Validation failed" when starting

A list of problems appears instead of cutting starting.

Other messages you may see at start:

Checking the FR Recorder shared folder by hand

When cutting starts, the CutterV2 signs in to each FR Recorder's hidden administrative share automatically. If that fails, it is useful to test the same thing yourself.

In Windows Explorer or Total Commander, type the recorder's address:

\\192.168.1.60\

If the share opens without asking for anything, the network path is fine and the problem lies elsewhere.

If Windows asks for a user name and password, you need the FR Recorder share credentials. They are not listed here — ask the Control Room team, or use the support assistant, which can supply them. The CutterV2 itself signs in with a built-in service account, so you never normally see this prompt.

If neither is accepted, or the address cannot be reached at all:

• Check the FR Recorder machine is switched on and on the network.
• Check that Windows file sharing is not blocked by a firewall between the machines.
• Check that the FR Recorder's share is still configured — reinstalling Windows on a recorder removes it.

Cutting is slow

In rough order of impact:

1. Make sure FFmpeg is being used

Check that Use FFmpeg for non-live recordings is ticked on the Settings tab, and that ffmpeg.exe is present in C:\FairReplay\CutterV2.

FFmpeg is many times faster than the internal engine, but it only applies to recordings that are finished. During a live event most recordings are still rolling, so most clips are cut the slow way — that is unavoidable. After the event everything is finished and everything is fast.

2. Adjust the number of cutting processors

More processors cut more clips at once, up to the point where the machine cannot keep up.

Set it in Number of Cutting Processors. It needs a restart.

3. Look at CPU throttling

If the CPU throttling threshold is low, processors spend their time waiting. Raising it speeds up cutting at the cost of a less responsive PC. See CPU Usage Throttling Threshold.

On a machine dedicated to cutting alone, you can untick throttling entirely. On a machine that also runs the Video Ingester, leave it on.

4. Look at the disk and the network

• Writing clips to a network drive is much slower than writing to a local disk.
• Reading recordings over a slow or congested network is often the real bottleneck. If the CutterV2 PC is on Wi-Fi and the recorders are on cable, that is your answer.
• An SSD for the output folder makes a clear difference when three processors write at once.

5. Reduce the workload

• Cut fewer camera angles with the Camera Angles box.
• Cut fewer contests with contest filters.
• Reduce Maximum mode time so clips are shorter.

Log files

Everything the CutterV2 does is written to disk, in far more detail than the on-screen log shows. The logs are in the installation folder, under logs, with one folder per day:

C:\FairReplay\CutterV2\logs\2026-08-07\

The folder is named for the date in yyyy-MM-dd form, so the most recent folder is the one at the bottom of the list.

One file sits outside the dated folders, directly in C:\FairReplay\CutterV2:

When something goes wrong with one particular clip, the matching processorN.log is the file to read: it names the source file, the calculated start and end, which engine was used, and what went wrong.

Getting help

Have these ready:

• The version from the title bar, for example 2026.06.30.115-f09df41.
• The exact error message, or a screenshot of it.
• The contest codes affected — double-click the ERRORS card to copy them.
• The log folder for the day.
• What changed recently: a new PC, a network change, a different venue.

The ? button on the Automatic cutting tab opens this documentation in your browser.