If you're trying to figure out how to fix roblox fps unlocker not working, you're definitely not alone. It's a super common headache for anyone who's used to playing at 144Hz or higher. There is honestly nothing worse than being used to silky-smooth gameplay and then suddenly finding yourself capped back at 60 FPS because the unlocker decided to take a day off. It feels like playing in slow motion once you've seen the light of high frame rates.
The thing about the Roblox FPS Unlocker (often called RBXFPSUnlocker) is that it's a third-party tool. Because it's not an official part of the Roblox client, every time Roblox pushes out an update—which happens pretty much every week—there's a chance things will break. Whether you're dealing with a black screen, the program simply not opening, or the frame rate staying stubbornly stuck at 60, I've got you covered. Let's walk through the most common fixes that actually work.
Check for a New Version First
The most frequent reason people search for how to fix roblox fps unlocker not working is simply that their version is outdated. Since Roblox updates their client constantly, the developers of the unlocker have to update their code to match. If your unlocker was working yesterday and stopped today, there's a 90% chance a new version was released on GitHub.
Go back to the official GitHub repository and check the "Releases" section. If you see a version number higher than what you're currently running, download it. You don't even really need to "uninstall" the old one—just close the old process, delete the old folder, and run the new .exe. It's a bit of a chore to do this every few weeks, but it's the nature of using unofficial mods.
The "Run as Administrator" Trick
Sometimes the fix is so simple it's almost annoying. Windows can be really picky about which programs are allowed to "inject" or modify the behavior of other running programs. Since the FPS unlocker essentially tells the Roblox engine to ignore its internal limits, Windows might block it if it doesn't have the right permissions.
Right-click on the rbxfpsunlocker.exe file and select Run as Administrator. If this fixes the problem, you can make it permanent. Right-click the file again, go to Properties, click the Compatibility tab, and check the box that says "Run this program as an administrator." Now, every time you open it, it'll have the clearance it needs to do its job.
Whitelist It in Your Antivirus
Windows Defender and other antivirus programs like Avast or Norton are notoriously aggressive toward the Roblox FPS Unlocker. They see a program trying to hook into another application's process and immediately think, "Wait, that looks like a virus!"
It's a false positive, but it'll stop the unlocker from working entirely. If your unlocker disappears or gives you an "Access Denied" error, your antivirus probably ate it. You'll need to go into your antivirus settings and add the folder where the unlocker is located to your Exclusions list. Once you've done that, you might need to redownload the file because the antivirus might have already quarantined or deleted the original executable.
Make Sure It's Actually Running in the System Tray
Sometimes the unlocker is working perfectly fine, but it just hasn't "hooked" into the game properly, or it's minimized. When you run the program, it doesn't usually pop up with a big window. Instead, it hides in your System Tray (the little arrow in the bottom-right corner of your taskbar, near the clock).
Find the little icon that looks like a small graph. Right-click it and make sure "Check for Updates" and "Unlock Roblox Player" are both checked. I've seen cases where the "FPS Cap" setting inside that menu somehow got set back to 60. Make sure it's set to "None" or whatever your monitor's refresh rate is (like 144 or 240).
Deal with Roblox's Built-in FPS Cap
Recently, Roblox actually added their own internal FPS cap setting in the game's menu. This has caused a lot of confusion. You might be running the unlocker, but the game's internal settings are fighting against it.
When you're in a game, hit Esc, go to Settings, and scroll down until you see Framerate Cap. If this is set to 60, it might be overriding your unlocker. Try setting this to the highest possible value or "Unlimited" if the option is there. In some cases, the built-in setting makes the external unlocker redundant, but many players still prefer the third-party tool because it tends to be more consistent for high-end rigs.
Try Changing Your Fullscreen Mode
Roblox has a weird relationship with fullscreen mode. Sometimes, if you're in "True Fullscreen" (which you usually toggle with Alt+Enter), the FPS unlocker won't kick in properly because of how Windows handles V-Sync in that mode.
Try switching to Windowed or Borderless Windowed mode to see if the frames jump up. If they do, you know the issue is related to your display settings. You can also try disabling "Fullscreen Optimizations" by right-clicking your Roblox shortcut, going to Properties > Compatibility, and checking the box for "Disable fullscreen optimizations." This is a classic fix for all sorts of gaming performance issues on Windows 10 and 11.
Check Your Graphics Card Settings
If your hardware is capped at the driver level, no amount of software unlocking will help. Both NVIDIA and AMD have settings in their control panels that can force a frame limit.
For NVIDIA users: 1. Right-click your desktop and open the NVIDIA Control Panel. 2. Go to Manage 3D Settings. 3. Look for "Max Frame Rate" and "Vertical Sync." 4. Make sure "Max Frame Rate" is Off and "Vertical Sync" is set to "Use the 3D application setting" or "Off."
If V-Sync is forced "On" in your GPU settings, it will lock your FPS to your monitor's refresh rate regardless of what the unlocker is trying to do.
Maybe It's Time to Switch to Bloxstrap?
If you've tried everything and you're still stuck on how to fix roblox fps unlocker not working, it might be time to move on to something better. A lot of the community has moved away from the standalone FPS unlocker in favor of Bloxstrap.
Bloxstrap is basically a "bootstrapper" or a custom launcher for Roblox. It includes a built-in FPS unlocker that is much more stable and doesn't break nearly as often. It also lets you do cool things like change the old death sound back to the "Oof" sound or use custom textures. Since it integrates directly with the way Roblox launches, it's way more reliable than a separate .exe running in the background. If you're tired of fixing the old unlocker every week, Bloxstrap is the way to go.
Final Thoughts
At the end of the day, getting high frame rates in Roblox shouldn't be this much of a chore, but that's just part of the PC gaming life. Most of the time, it's just a matter of downloading the latest update from GitHub or telling Windows Defender to leave the program alone.
If you followed these steps—checking for updates, running as admin, whitelisting it, and checking your GPU settings—you should be back to those sweet, high-FPS numbers in no time. If all else fails, seriously give Bloxstrap a shot. It saves a lot of troubleshooting time in the long run. Now get back in there and enjoy your lag-free gaming!