Epic Games Launcher or Unreal Engine Install Stuck on Percent - Cache, Permissions, and Antivirus Exclusions Fix

Problem: Epic Games Launcher download or Unreal Engine installation gets stuck at a percentage (commonly 0%, 7%, 82%, or 90%) and does not continue even after waiting.

This usually happens when cached launcher state is corrupted, the install path is blocked by permissions, or antivirus software is scanning and locking Unreal files during extraction.

Quick fix checklist

Fully close Epic Games Launcher (including background process).
Clear Epic launcher webcache folders.
Run Epic Games Launcher as administrator once.
Verify free disk space and write permissions on install drive.
Add temporary antivirus exclusions for Epic and Unreal install folders.
Resume install and verify progress moves past the stuck percentage.

Root cause summary

Most stuck-percent installs are caused by one or more of these:

Corrupt launcher cache - stale metadata blocks normal download/extract flow.
Insufficient write access - launcher cannot create or patch files in target folder.
Real-time antivirus scan lock - extracted files are quarantined or delayed.
Storage constraints - not enough free space for both compressed and extracted content.
Interrupted prior install state - partial manifests confuse resume logic.

Step-by-step fix

Step 1 - Exit Launcher completely

Close Epic Games Launcher, then confirm no Epic background process is still running in Task Manager.

If it remains active, end it manually before continuing.

Verification: Launcher process is no longer listed.

Step 2 - Clear Epic Games Launcher cache

Open %localappdata% and navigate to EpicGamesLauncher\Saved\.

Delete cache folders such as:

webcache
webcache_4430 (if present)
any old webcache_* variants

Do not delete your game projects. This step only resets launcher web/cache state.

Verification: New cache folders are regenerated when launcher starts.

Step 3 - Relaunch with elevated permissions

Start Epic Games Launcher with Run as administrator.

Then retry installation in a folder path you fully control (for example a dedicated game dev drive folder, not a restricted system location).

Common mistake: Installing to a protected folder while using a standard user token.

Step 4 - Validate disk and folder write access

Before resume:

Confirm enough free disk space for download + extraction overhead.
Check target folder is writable by your user account.
Avoid long or unusual path names that can cause extraction issues.

If needed, create a clean directory like D:\Epic\UE_5_7.

Verification: You can manually create and delete a test file in the target path.

Step 5 - Add antivirus exclusions temporarily

Real-time scanning often freezes install progress near larger chunk extraction points.

Temporarily add exclusions for:

Epic Games Launcher install folder
Unreal Engine target install folder
Epic download cache folder

After install finishes and verifies, re-enable your usual security policy and keep only the minimum required exclusions.

Step 6 - Resume or restart install cleanly

Back in Launcher:

Resume the existing install.
If still stuck instantly at same percentage, remove that engine version entry and start fresh.
Let verification complete after download.

Verification: Install moves beyond the previously stuck percentage and reaches completed/verified state.

Alternative fixes

Switch to a different drive with more free space and less aggressive endpoint protection.
Disable VPN/proxy temporarily if manifest retrieval fails repeatedly.
Sign out/in Epic account to refresh entitlement and manifest session.
For managed corporate devices, ask IT to whitelist Epic/Unreal paths centrally.

Prevention tips

Keep at least 2x temporary free space for large Unreal installs and updates.
Use a stable dedicated install location for all engine versions.
Avoid force-closing launcher during verification/extraction.
Keep Windows and storage drivers updated before major engine install runs.
Schedule large installs outside active antivirus full-scan windows.

FAQ

Why does install freeze near 82% or 90% specifically?
These stages often involve large extraction and verification passes, where disk and antivirus contention is highest.

Should I always run Epic Launcher as admin?
Not always, but it helps diagnose permission problems quickly. If normal mode fails and admin mode works, fix folder ACLs.

Can I delete only one cache folder instead of all webcache variants?
Yes, but clearing all webcache variants is usually more reliable when the install state is corrupted.