How to post a Bug Report

Roblox · February 19, 2020, 6:52pm

Reports without the following information will not be investigated!

Basics

Your bug reports must have:

A descriptive title - Engineers should know what the bug is before opening the thread.
A detailed description of the bug - Information on what the bug is and what you expect to occur.
Where the bug happens - Does the bug only happen with specific places / users / groups / etc?
When the bug started happening - Dates help find the version causing it so it can be fixed faster.
Screenshots and videos of the bug - Include screenshots / videos of the bug happening; they’re extremely helpful and more descriptive than words alone.

Reproduction Steps

Provide step-by-step instructions engineers can take that cause the bug to happen.
These steps must be:

Minimal - If you have a complicated repro, simplify as much as possible.
Specific - The steps must be clear, detailed, and not open to misinterpretation. Don’t assume engineers know what you mean.
Consistent - Ideally, your steps reproduce the issue 100% of the time. Please specifically mention how often your steps reproduce the bug (100% / 50% / Rarely?)

For bugs with complicated setups or conditions, attach a minimal place file to your thread that can be used to reproduce the bug. Provide repro files instead of screenshots for bugs that only happen for certain code / instances / etc!

Required Information

Crashes or Freezes - Include a repro. If you cannot provide a 100% repro, provide a dump.
Performance Problems - Include a microprofiler dump, and your system information if the problem is specific to your computer.
Problems running Roblox / Studio or error popups - Include relevant log files.
Graphics Problems - Include your system information.
Problems specific to a Place / User / Group / etc - First try to isolate the issue to a repro file. Otherwise, include direct links to the affected assets; engineers will not know what “my game” or “game-name” refer to.
Backend Problems (e.g. Team Create connection failures) - Provide information to help find the problem on Roblox’s side.

Roblox · April 1, 2020, 6:34am

Example Bug Reports

Studio Bugs: Studio crashes when resizing any 5x5x5 part

Roblox Studio will always crash when you try to resize a 5x5x5 size part using the resize tool, the properties widget, or command bar. Parts of any other size do not crash.

This happens only in Studio.
This started happening on December 20.

Repro

With Resize tool or Properties widget:

Create a part and set its size to 5,5,5 using the properties widget.
Select the part and choose the resize tool, or select the size field in the properties widget.
Try to resize the part, Studio will crash.

With script run from command bar:

local p = Instance.new("Part", workspace)
p.Size = Vector3.new(5,5,5)
p.Size = Vector3.new(10,10,10) -- Crashes

Both methods will crash 100% of the time.

Crash Dump

https://devforum.roblox.com/t/link-to-dm-to-studio-bug-files/######

Engine Bugs: Character spawns with green head in live games

When your character spawns in-game, your head will always be green.
This does not happen in Studio, it only happens in a real game.

This started happening today.
As far as I can tell, this happens 100% of the time with both R6 and R15 characters.

Repro

Join any game, this default baseplate for example: https://www.roblox.com/games/testing-game-id-here.
Notice your head is green when you spawn.

Engine Bugs: Glass material renders completely black

In-game and in Studio the glass material renders completely black.

This happens 100% of the time for me, but other people I’ve asked don’t have this problem.
This has been happening since I got my new GPU on December 20.

Specs

OS: Windows 10 Home
GPU: NVIDIA GeForce GTX 1070

This is what a default part inserted in Studio and changed to the glass material looks like for me.

Engine Bugs: Lag when creating ParticleEmitters

Sometimes when a ParticleEmitter is created by either the server or the client, Roblox will have a brief lag spike. Parenting the ParticleEmitter is not required, simply creating it with a script will cause the problem.

This started happening today.
This happens in-game, and in Studio about 50% of the time a ParticleEmitter is created.
This only happens with ParticleEmitters.

Repro

Run the below code.
Roblox will freeze briefly about 50% of the time after “Creating” is printed.

while wait(1) do
	print("Creating")
	local p = Instance.new("ParticleEmitter")
	print("Created")
end

ParticleEmitterLagExample.rbxl (17.2 KB)

Demonstration

If you look closely, you can see Roblox freezing briefly.

Microprofiler Dump

You can clearly see one of the lag spikes in this dump.
microprofile-20191220-022927.html (1.1 MB)

Roblox · April 1, 2020, 6:19am

How to Find Log Files

NOTE:

These log files may contain sensitive information, so it’s important they’re NOT posted publicly.
It is important you identify the correct log files! Make sure you are sorting by last modified or finding the most recent logs by timestamp.

Roblox / Studio successfully launches

Windows
- Go to %localappdata%/Roblox/logs.
Mac
- Go to ~Library/Logs/Roblox.
- Library can be found under Go > Library (you may need to hold down Option if it isn’t there).
Sort the directory you opened by Last Modified.
Take the latest log_xxxxx_x.txt file.

Roblox / Studio does not launch properly

Include the logs from the above section if they exist.
Windows
- Go to %localappdata%\Temp and sort the folder by Last Modified
- Take the latest two RBX-xxxxxxxx.log files
Mac
- Go to ~Library/Logs/Roblox and sort the folder by Last Modified
- Library can be found under Go > Library (you may need to hold down Option if it isn’t there).
- Take the latest bootstrapper_xxxxxx_x.txt file.

If the issue is freezing, loading forever, or similar, wait a few minutes before following these instructions to copy the log files so that there is enough time for long operations to get logged.

For Studio issues, DM the log files to the Studio Logs / Crash Dumps group, and include a link to the DM in your thread.

For issues with the Roblox app used to play games, wait for an engineer to reply and DM the files to them.

Roblox · April 1, 2020, 6:19am

How to Get Dumps

NOTE:

These dump files may contain sensitive information, so it’s important they’re NOT posted publicly.

How to find dumps automatically generated on crash

Windows
- Go to %localappdata%/Roblox/logs and sort the folder by Last Modified.
- Take the first .DMP file (if you don’t see one, it may be in /archive).
Mac
- Open the terminal and run open $TMPDIR, sort the folder by Last Modified.
- Take the first .DMP file.

How to generate dump files for freezes/hangs

(Only available on Windows)

Open the Task Manager with Ctrl+Shift+Escape.
Find RobloxStudio in either the Details (Windows 10) or Processes tab.
Right click and select “Create dump file”.
Take the .DMP file shown in the proceeding dialog.

Generate ~3 or so dump files like this, each a few minutes apart

Once you have the dump file(s) from either of the above steps, they are too large to share on the forum. You will need to upload them to a file hosting service (e.g. Google Drive, Dropbox).

For Studio issues, DM the dump files to the Studio Logs / Crash Dumps group, and include a link to the DM in your thread.

For issues with the Roblox app used to play games, wait for an engineer to reply and DM the files to them.

Roblox · February 19, 2020, 6:29pm

How to Get Microprofiler Dumps

If Roblox or Studio is stuttering or running slowly, but not completely frozen, you can provide a microprofiler dump to help engineers find the problem.

Open the microprofiler with Ctrl+F6.
Once the stuttering / slowness happens, press Ctrl+P to pause the microprofiler.
From the top menu bar, click Dump > 32 frames.
On Windows, go to %USERPROFILE%.
On Mac, go to Go > Home.
Sort the folder by Last Modified.
Find the latest microprofile-yyyymmdd-xxxxxx.html file.
Open the file in your browser and make sure that it captured the performance problem (there should be a spike near the right side of the timeline at the top).

You can directly upload this HTML file to your bug report.

Roblox · April 1, 2020, 6:20am

Providing System Information

Minimal Information

This information is usually enough for a bug report unless asked for by an engineer.

If you’re on Mac, engineers prefer if you follow the steps below, even if you already know your system information. If you’re on Windows and know your system information, you can just include your OS, CPU & GPU models, and RAM amount in your bug report (otherwise, follow the steps below).

Mac:

Click the Apple icon in the top left of the screen and select About This Mac.
Include a screenshot of the dialog that appears.

Windows 10

Open Task Manager with Ctrl + Shift + Escape.
Go to the Performance tab.
Click the CPU, Memory, and GPU tabs and include the information in the top-right in your bug report.
- e.g. Intel® … @ 3.0 GHz, 16 GB, NVIDIA GeForce GTX 970

Older versions of Windows

Follow the instructions in the Advanced section, below.
Instead of clicking “Save All Information”, include the values from Operating System, Processor, and Memory on the System page, and the Name from the Display 1 page in your bug report

Advanced Information

Mac

Follow the instructions in the Minimal section, above.
Click System Report....
Click File > Save.
This full system report contains sensitive information, so it’s important it’s NOT posted publicly.
- For Studio issues, DM the saved file to the Studio Logs / Crash Dumps group, and include a link to the DM in your thread. For issues with the Roblox app used to play games, wait for an engineer to reply and DM the files to them.

Windows

Type dxdiag in the start menu (or in the Run dialog) and press enter.
If a popup appears about “digitally signed drivers”, click “Yes”.
Click “Save All Information” and attach the generated DxDiag.txt file to your bug report.

Roblox · February 19, 2020, 6:48pm

Helping Correlate Backend Logs

If there is a problem on the backend (Roblox’s side), engineers will need to investigate their own logs. To find them (since they have too many to look through manually), they need:

The userId of the account you were using when you had the issue.
The placeId / gameId of the game you were using when you had the issue.
The date and time (including timezone) you had the issue. Be as precise as possible.
Your log files.
As much information that was shown to you as possible.
- e.g. screenshots of errors and popups, HTTP status codes displayed in the UI, log files, etc.