"Failed to load library" means Roblox cannot find or use a Windows system file it needs. The popup usually names the file, most often MFPlat.dll or urlmon.dll, and it stops Roblox from launching or installing at all.
This is a Windows-only error. The DLL name in your popup decides where to start, so read it before you change anything.
| The error names | Do this |
|---|---|
| MFPlat.dll or EVR.dll | Install the Media Feature Pack |
| urlmon.dll, SensApi.dll, or any other DLL | Work through fixes 1 to 4 below |
If the error names MFPlat.dll or EVR.dll, install the Media Feature Pack
MFPlat.dll and EVR.dll are Windows Media Foundation files. Windows N and KN editions ship without them on purpose, so Roblox has nothing to load.
Check your edition first. Open Settings > System > About and look at the edition name. If it ends in "N", this is your fix.
- Open Settings and go to Apps > Optional features.
- Click View features on Windows 11, or Add a feature on Windows 10.
- Search for Media Feature Pack.
- Select it and install it.
- Restart your PC, then launch Roblox.
If your edition does not end in "N", or the pack is already installed, move on to the fixes below.
For any other DLL, repair Windows files and reinstall Roblox
urlmon.dll, SensApi.dll, or any other name in the popup points to a file that is corrupted, missing, or blocked. The Media Feature Pack does not cover these files, so skip it. Run these fixes in order and test Roblox after each one.
1. Repair Windows system files
Windows can rebuild its own damaged files, including the DLL Roblox is asking for.
- Search for "cmd" in the Start menu, right-click Command Prompt, and choose Run as administrator.
- Run
DISM /Online /Cleanup-Image /RestoreHealthand wait; it can take 10 to 20 minutes. - Run
sfc /scannowand let it finish. - Restart your PC and launch Roblox.
2. Reinstall Roblox cleanly
A broken install can throw this error even when Windows itself is fine. Wiping the leftover files matters as much as the uninstall.
- Uninstall Roblox from Settings > Apps > Installed apps.
- Press Win + R, type
%localappdata%, and press Enter. - Delete the Roblox folder.
- Install the other version: grab the desktop installer from roblox.com/download if you had the Microsoft Store version, or install from the Store if you had the desktop app.
Switching versions helps because they install into different locations, so the new copy skips whatever broke the old one. The same clean reinstall also clears other launch failures like An Error Occurred and Roblox Cannot Continue.
3. Restore Roblox files from antivirus quarantine
Some antivirus tools quarantine Roblox files during installation, which leaves Roblox missing pieces.
- Open your antivirus and find its quarantine or protection history section.
- Restore any Roblox files listed there.
- Add the Roblox folder to your antivirus exclusions so it stays untouched.
4. Update Windows and your graphics drivers
Old system files and drivers can keep the error coming back after everything else is fixed.
- Open Settings > Windows Update and install every pending update.
- Update your graphics driver through the NVIDIA, AMD, or Intel app, or from the maker's website.
- Restart your PC.
If Roblox still will not load
Do not download the missing DLL from a DLL website. Those files are unverified, often the wrong version, and sometimes carry malware. Every safe copy of these libraries comes from Windows itself, which is exactly what the fixes above restore.
If nothing worked, contact Roblox Support with the exact error text, your Windows version, and the steps you tried. Support may also walk you through last-resort options like a new Windows user account or System Restore.
If Roblox now opens but crashes later, that is a different problem: the fixes for An Unexpected Error Occurred and Roblox Needs to Quit and Roblox keeps closing on PC pick up from there. More launch and install problems are collected in Roblox errors and fixes.
