The EntitlementDataStore.ecml file:

Location: C:\ProgramData\Intuit\Entitlement Client\v8\EntitlementDataStore.ecml (or v6 if v8 doesn't exist). This file stores the result of QB's last license verification against Intuit's servers — your product key, expiry, and activation status. When this file is corrupted, missing, or contains data for a different machine, QB can't initialize and reports Error 3371. Deleting it forces QB to create a new one by re-verifying with Intuit's servers. Your company data is unaffected.

3371 vs Subscription Expired: Both involve license/entitlement files, but differ. Error 3371 = the ECML file itself is corrupted or missing — QB can't even read the license data to determine if it's valid or expired. Subscription Expired = the ECML file is readable but contains expired subscription data. Fix for 3371: delete ECML → re-register. Fix for Subscription Expired: renew via CAMPs OR sync license online. If you delete the ECML and QB says "subscription expired" after re-registering, you have a genuine subscription expiry to resolve separately.

Corrupted EntitlementDataStore.ecml

Primary cause — the ECML file was corrupted by an abrupt shutdown while QB was writing to it, a disk error, malware, or antivirus activity. QB tries to read the file on startup, finds invalid data, and reports Error 3371. Deleting the file and re-registering QB creates a clean, valid ECML file.

QB Installed But Never Activated

If QB was installed on a machine but the activation step was skipped or failed, the ECML file either doesn't exist or contains incomplete activation data. QB reports 3371 every time it launches because it can't confirm the product is licensed. Registering QB with the license and product numbers from the original purchase resolves this.

Company File Opened on Different Machine

The ECML file stores machine-specific license data. When a company file is moved to a different machine where QB isn't properly registered, the ECML on the new machine doesn't match the company file's activation expectations. Re-registering QB on the new machine with the original license number resolves this.

ECML File Deleted or Quarantined by Antivirus

Antivirus software can flag the ECML file as potentially unwanted (it's an unusual file type and resides in a system folder) and quarantine or delete it. Without the ECML, QB reports 3371 on every startup. Check the antivirus quarantine log for the ECML file → restore it or exclude the Entitlement Client folder from scanning.

Hardware Change or System Migration

Significant hardware changes (motherboard replacement, OS reinstall, or migration to a new PC via imaging) can invalidate the ECML file because it contains hardware fingerprint data. QB's license is tied to both the product key and the machine's hardware profile. After a major hardware change, QB reports 3371 — re-registering binds the license to the new hardware profile.

Damaged QB Installation

A corrupted QB program installation can fail to write or read the ECML correctly. The QB installer creates or updates the ECML during installation — if the installation was interrupted or damaged, the ECML may be invalid. Running the QB Install Diagnostic Tool or a repair installation addresses this variant.

METHOD 1 Delete EntitlementDataStore.ecml + Re-register QB Resolves virtually all Error 3371 cases

METHOD 2 Check Antivirus Quarantine + Exclude Entitlement Folder ECML quarantined or deleted by antivirus

METHOD 3 Run QB Install Diagnostic Tool + Repair QB Installation Damaged QB installation preventing ECML creation

METHOD 4 Sync License Data Online (if 3371 recurs after ECML deletion) Error returns after initial fix — stale data

Will I lose my company data if I delete the EntitlementDataStore.ecml file?

No. The EntitlementDataStore.ecml file contains only licensing and activation data — it has no connection to your accounting data or company files. Your company file (.QBW) is stored in a completely different location (typically C:\Users\[username]\Documents\Intuit\QuickBooks\ or wherever you saved it). Deleting the ECML file only removes the cached license verification data. When QB asks you to re-register, you're simply recreating this license cache from Intuit's servers using your existing license number. All company data, transaction history, payroll records, and settings remain completely intact.

Where do I find my QuickBooks license number if I don't have it?

There are several places to find your QB license number: (1) Press F2 (or Ctrl+1) while QB is open — this opens the Product Information window showing both the License Number and Product Number, but 3371 prevents QB from opening. (2) Log into camps.intuit.com with the Intuit account that purchased QB — your license is listed under Products & Services. (3) Check the original purchase confirmation email from Intuit. (4) If QB was purchased through a ProAdvisor, contact them — they have access to your license details. Have both the License Number (15 digits) and Product Number (8 digits formatted as XX-XXXX) ready before deleting the ECML file.

How many PCs can I install QuickBooks on with one license?

A standard QuickBooks Desktop license allows installation on up to 3 computers (as per Intuit's End User License Agreement for personal use), provided QB is not used simultaneously on more computers than your purchased user license covers. If you see Error 3371 after installing QB on a new machine, it may be because you've exceeded the activation limit. In this case, QB will prompt you to deactivate on another machine or contact Intuit to increase your seat count. Log into CAMPs to view your active installations and deactivate old machines you're no longer using.