[SPZ2-6305] [1.0.3-rc3] Train delivery sometimes happens in slow motion.

[cold pivot]

There's a savegame and a recording attached.
The issue reproduces for me when I load that savegame 100% even after game restart. The trains coming from the north are jumping into the vortex in a slow-motion for no apparent reason.
Even if I wait when there are no trains from other directions for several seconds, these trains are slow.

Issue has occured multiple times but resolved eventually. I think once the queue drain, the new trains will jump in normally until the clogging happens again.

[west cairn]

Thank you for reporting this bug! Our team will review your report soon.
Feel free to add more details in follow-up messages — we're also scanning for duplicate reports automatically now.
📨 There are currently 67 reports awaiting team review. Due to the high volume, it may take a little longer for us to get to yours.

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• Windows: %USERPROFILE%\AppData\LocalLow\tobspr Games\shapez 2\Player.log

[west cairn]

💾 insane playthrough

Started in

1.0.2-rc1

Last played in

1.0.3-rc3

Scenario

Classic - Insane

Seed

810

Research

65%

Buildings

382,255

Completed

No

1. [SPZ2-3092] — ✨ 82% similar

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When a train is tailgating another train on the same rail, it becomes excessively slow. This occurs when trains are following closely behind each other on the track. The issue was observable in the provided save file. A minimum speed for trains was added to fix this behavior, ensuring trains maintain adequate speed even when following other trains closely.

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💬 Threads: [0.1.0-PRE8-RC1] Trains jump into vortex

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"Negative Train Velocity" Exception thrown when Trains are running
Done • Priority: Highest • Fix: 4 - Early Access • Resolution: Done

A "Negative Train Velocity" exception is thrown repeatedly when Trains are running on Rails. The issue appears to trigger when placing or merging Rail segments while connecting four colored Train Stops. The exception continues to occur as Trains follow their Route. The Player.log shows additional unrelated errors including savegame version mismatches and Blueprint Library deserialization failures. The issue has been verified as fixed and could not be reproduced.

Found 6 similar reports • Searched 3,584 reports • Use /check-duplicates to recheck

[faint shoal]

Thanks for the report Wataru! Do you remember where the clog occurred which caused the issue?

[west cairn]

❓ We need a bit more information to investigate this bug. Please check the comments above and provide the requested details.

📋 Log files help us investigate issues. You can find yours here:
• Windows: %USERPROFILE%\AppData\LocalLow\tobspr Games\shapez 2\Player.log

💾 Savegame files (.spz2) are very helpful if relevant to the issue!
Export via Main Menu → Play → click the download icon on the relevant savegame.
You can also find them here:
• Windows: %USERPROFILE%/AppData/LocalLow/tobspr Games/shapez 2/

[cold pivot]

Here's the log

[west cairn]

✅ Thank you for providing further information, our team will have a look again!

[west cairn]

📋 Log File Analysis

Thanks for attaching your log file — no errors have been found at a first glance.

[cold pivot]

It's clogged at the jump point near the vortex. I don't know how or when.

My guess, too many trains approached the vortex at once, which caused this line to slow down. But the issue is that it doesn't speed back up when there's no contention.

[light totem]

That is certainly weird to watch happening.

[west cairn]

🎫 Many thanks for reporting this issue! We have created an internal ticket for further investigation and will keep you updated. The internal ticket ID is SPZ2-6305 for reference. If you want to provide further information, just comment on this thread.