How can I fix a failed or looping MetaDefender Core module update by clearing the package cache?

This article applies to all MetaDefender Core V4 and V5 releases deployed on Windows systems.

When should you use this?

  • Engine/module updates fail, are stuck, or engines behave inconsistently.
  • You need a full clean reset of engine and update data to force fresh downloads.
  • In some cases, after a license undergoes modifications, remnants of old engines that are no longer reflected in the new license can still exist on the drive.

Option A - Standard reset (cached modules/engines)

Stop the service (elevated Command Prompt) net stop ometascan (Or via Services → OPSWAT MetaDefender Core → Stop__.)

  1. Delete update cache Delete all contents of: C:\Program Files\OPSWAT\MetaDefender Core\data\updates
    (Delete files inside only; keep the folder.)
  2. Delete engine folders Delete all contents of: C:\Program Files\OPSWAT\MetaDefender Core\data\engines
    (Delete files inside only; keep the folder.)
  3. Start the service (elevated Command Prompt) net start ometascan (Or via Services → Start__.)
  4. Trigger module updates In Core UI go to Inventory → Modules and click the Install all (blue) button.
  1. Verify Ensure all modules show Up to date and sample scans succeed.

Option B - Full reset including old‑license leftovers (recommended if engines don’t match entitlements and option A fails to clean the unlicensed engines)

  1. Deactivate the Core license In the Core UI, open the License page and Deactivate. (If OCM manages your license, temporarily prevent OCM from auto‑pushing an old license until step 3 is complete.)
  2. Stop the service (elevated Command Prompt) net stop ometascan (Or via Services → OPSWAT MetaDefender Core → Stop__.)
  3. Delete update cache Delete all contents of: C:\Program Files\OPSWAT\MetaDefender Core\data\updates
    (Delete files inside only; keep the folder.)
  4. Delete engine folders Delete all contents of: C:\Program Files\OPSWAT\MetaDefender Core\data\engines
    (Delete files inside only; keep the folder.)
  5. Start the service (elevated Command Prompt) net start ometascan (Or via Services → Start__.)
  6. Re‑activate the license In the Core UI, Activate the correct license (online or offline as applicable).
  7. Trigger engine updates Go to Inventory → Modules and click Install all (blue button). Core will now download the engine set that matches your license.
  8. Verify Confirm engines match your entitlements and show Up to date.

Notes

  • This resets local engine/update data only; Core configuration remains intact.
  • For offline sites, prepare the required offline update packages and license files before you start.

If Further Assistance is required, please proceed to log a support case or chat with one of our support engineers.
Type to search, ESC to discard
Type to search, ESC to discard
Type to search, ESC to discard
Next to read:
Is there a virus test I could use to test MetaDefender Core engines?
On This Page
How can I fix a failed or looping MetaDefender Core module update by clearing the package cache?When should you use this?Option A - Standard reset (cached modules/engines)Option B - Full reset including old‑license leftovers (recommended if engines don’t match entitlements and option A fails to clean the unlicensed engines)Notes