You’re not dealing with some mysterious “ERP is slow” ghost. SQL is literally telling you it’s tripping over its own permissions.

That error is the key:

Cannot execute as the database principal “dbo”

Translation: something in your SQL instance is trying to run as dbo, and SQL has no idea who that actually maps to anymore. That’s broken ownership.

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What’s actually going on

This usually happens when: • A database got restored from another server • The original owner login doesn’t exist on this instance • Or the owner SID is orphaned

So now anything using Service Broker, jobs, queues, or stored procedures with EXECUTE AS is failing repeatedly

And yeah, that will slow your ERP down because: • retries • queue failures • jobs choking in the background

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Stop guessing and check this first

Run this in SQL:

SELECT name, SUSER_SNAME(owner_sid) AS owner FROM sys.databases;

If you see: • NULL • or some weird old account

Congrats, that’s your problem.

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Fix it (this is usually all it takes)

Set the DB owner properly:

ALTER AUTHORIZATION ON DATABASE::YourDBName TO sa;

Or if you don’t like using sa, use a valid login that exists.

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If it’s tied to Service Broker / queues

That “enqueueing a message in the target queue” line is a giveaway.

Check: • SQL Agent jobs • Service Broker queues • Any ERP-related messaging components

They’re probably running under EXECUTE AS OWNER or similar

If owner is busted → everything using that context fails

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Also check orphaned users (because why not)

EXEC sp_change_users_login 'Report';

If you see users not mapped to logins, fix them.

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Reality check

You’re not fixing “performance” here. You’re fixing a broken identity/permission issue that’s causing the performance problem.

If you ignore that and start tuning indexes or throwing more CPU at it, you’re just polishing a broken system.

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TL;DR • Your DB owner is likely invalid • SQL can’t impersonate dbo • Background processes are failing and slowing things down • Fix the DB owner → errors stop → performance likely stabilizes

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If you want, drop what ERP this is and I’ll tell you exactly where it’s probably breaking, because some of them are notorious for this.