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FastFlags (FFlag, DFInt, FString, FLog)

Engine configuration variables read by RobloxPlayerBeta.exe from ClientAppSettings.json at startup.

Glossary • Updated 17 October 2026 • 1 min read

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Bloxstrap requires the Microsoft .NET 6 Desktop Runtime to be installed

Frequently asked questions • Release notes

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What FastFlags (FFlag, DFInt, FString, FLog) means in Bloxstrap

Engine configuration variables read by RobloxPlayerBeta.exe from ClientAppSettings.json at startup.

Prefixes denote type and behavior: `FFlag` (boolean true/false), `FInt` (integer), `FString` (string), `FLog` (logging channel), and `D` prefix (`DFInt`, `DFFlag`) for dynamic flags that Roblox engineers can toggle.

Where you encounter this in the app

Bloxstrap wraps low-level Roblox configuration files, log watchers, and registry handlers into a clean WPF settings menu so you rarely need to edit raw files by hand.

Download the latest Windows installer at /download or browse the Engine and Setup hubs for step-by-step guides.

Frequently asked questions

What is FastFlags (FFlag, DFInt, FString, FLog)?

Engine configuration variables read by RobloxPlayerBeta.exe from ClientAppSettings.json at startup. Prefixes denote type and behavior: `FFlag` (boolean true/false), `FInt` (integer), `FString` (string), `FLog` (logging channel), and `D` prefix (`DFInt`, `DFFlag`) for dynamic flags that Roblox engineers can toggle.

Does this modify the Roblox game executable?

No. Bloxstrap only interacts with official configuration files, asset directories, and log files on disk.

Get more out of Roblox

Bloxstrap is an alternative launcher for Roblox with extra features and mods.

Download for Windows

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