Critical SQL Server 2019 crash – EXCEPTION_ACCESS_VIOLATION (c0000005) in Query Optimizer – request for on‑demand hotfix

Question

Critical SQL Server 2019 crash – EXCEPTION_ACCESS_VIOLATION (c0000005) in Query Optimizer – request for on‑demand hotfix

Paweł Cisło 0

We are experiencing rendom/repeated SQL Server Engine crashes on SQL Server 2019 (RTM‑CU32‑GDR, build 15.0.4455.2). The system terminates due to an unhandled EXCEPTION_ACCESS_VIOLATION (c0000005).

SQL restarts after the issue.

We believe The crash occurs during query compilation, not execution.

We need an on-demand hotfix for this critical engine crash.

SQL Server 2019 (RTM‑CU32‑GDR), KB5068404, Build 15.0.4455.2

OS: Windows Server 2019 Standard 10.0.17763 (VM / Hypervisor)

No CLR assemblies

No third‑party DLLs

No xp_* usage

Random Error

Paweł Cisło 0 Reputation points

2026-02-16T11:08:31.0466667+00:00

No Available CU
Akhil Gajavelly 1,570 Reputation points Microsoft External Staff Moderator

2026-02-17T10:21:47.2833333+00:00
Hi @Paweł Cisło ,

Since you’re already on the latest available CU for SQL 2019 and there are no further updates, this isn’t something that can be fixed from our side.

An EXCEPTION_ACCESS_VIOLATION in the Query optimizer is almost always an engine-level issue. There’s no configuration change or tweak that will reliably resolve it.

Because SQL Server 2019 is out of mainstream support, the only realistic options are:

Open a Microsoft support case (if your contract allows private hotfixes), or

Plan an upgrade to a supported version.

There’s no public hotfix available for this build.

Thanks @Erland Sommarskog for pointing out the support lifecycle angle that’s really the key factor here.

Thanks,
Akhil.
Akhil Gajavelly 1,570 Reputation points Microsoft External Staff Moderator

2026-02-20T04:38:35.9466667+00:00

Hi @Paweł Cisło ,

Just checking back on this. Were you able to open a Microsoft support case or review upgrade options? Since this is an engine-level access violation and SQL 2019 is out of mainstream support, there unfortunately isn’t anything further the community can provide beyond that path.

If you’ve gathered dump files or received feedback from Microsoft, feel free to share an update that may help others facing something similar.

Thanks,
Akhil.
Paweł Cisło 0 Reputation points

2026-02-20T07:44:50.6733333+00:00

Hello @Akhil Gajavelly ,
Unfortunately, I can't report this to Microsoft Support - no software assurance. Anyway Upgrading would be a more cost-effective solution, so we're resuming the upgrade process. Currently, this issue isn't occurring frequently enough to be a permanent issue. Thank you for your advice and consultation – even if it doesn't resolve the issue completely, your support is still needed. Thank you.
Akhil Gajavelly 1,570 Reputation points Microsoft External Staff Moderator

2026-03-11T04:38:27.4033333+00:00

Hi @Paweł Cisło,

Thanks for the update, and I’m glad to hear the upgrade process is moving forward.

Given the circumstances, that’s a reasonable approach. Since the crashes are not occurring frequently and SQL Server 2019 is already out of mainstream support, upgrading to a newer supported version should help avoid potential engine-level issues like this in the long run.

Thank you for sharing the outcome with the community. It will definitely help others who may encounter similar situations.

Thanks,
Akhil.

1 answer

Your answer

Paweł Cisło 0 Reputation points

2026-02-16T11:08:31.0466667+00:00

No Available CU
Akhil Gajavelly 1,570 Reputation points Microsoft External Staff Moderator

2026-02-17T10:21:47.2833333+00:00

Hi @Paweł Cisło ,

Since you’re already on the latest available CU for SQL 2019 and there are no further updates, this isn’t something that can be fixed from our side.

An EXCEPTION_ACCESS_VIOLATION in the Query optimizer is almost always an engine-level issue. There’s no configuration change or tweak that will reliably resolve it.

Because SQL Server 2019 is out of mainstream support, the only realistic options are:

Open a Microsoft support case (if your contract allows private hotfixes), or

Plan an upgrade to a supported version.

There’s no public hotfix available for this build.

Thanks @Erland Sommarskog for pointing out the support lifecycle angle that’s really the key factor here.

Thanks,
Akhil.
Akhil Gajavelly 1,570 Reputation points Microsoft External Staff Moderator

2026-02-20T04:38:35.9466667+00:00

Hi @Paweł Cisło ,

Just checking back on this. Were you able to open a Microsoft support case or review upgrade options? Since this is an engine-level access violation and SQL 2019 is out of mainstream support, there unfortunately isn’t anything further the community can provide beyond that path.

If you’ve gathered dump files or received feedback from Microsoft, feel free to share an update that may help others facing something similar.

Thanks,
Akhil.
Paweł Cisło 0 Reputation points

2026-02-20T07:44:50.6733333+00:00

Hello @Akhil Gajavelly ,
Unfortunately, I can't report this to Microsoft Support - no software assurance. Anyway Upgrading would be a more cost-effective solution, so we're resuming the upgrade process. Currently, this issue isn't occurring frequently enough to be a permanent issue. Thank you for your advice and consultation – even if it doesn't resolve the issue completely, your support is still needed. Thank you.
Akhil Gajavelly 1,570 Reputation points Microsoft External Staff Moderator

2026-03-11T04:38:27.4033333+00:00

Hi @Paweł Cisło,

Thanks for the update, and I’m glad to hear the upgrade process is moving forward.

Given the circumstances, that’s a reasonable approach. Since the crashes are not occurring frequently and SQL Server 2019 is already out of mainstream support, upgrading to a newer supported version should help avoid potential engine-level issues like this in the long run.

Thank you for sharing the outcome with the community. It will definitely help others who may encounter similar situations.

Thanks,
Akhil.

Answer 1

Erland Sommarskog 133.1K MVP Volunteer Moderator

SQL 2019 is out of mainstream support. To get a hotfix for this problem, you would need a really good support contract. In fact, I don't know if there are support contracts that includes hotfixes for non-security issues for versions out of mainstream support. But if there are, they are likely to come with a stiff price tag.

But I am just speculating. Use the support contract that you have and open a case to see where it takes you.

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Critical SQL Server 2019 crash – EXCEPTION_ACCESS_VIOLATION (c0000005) in Query Optimizer – request for on‑demand hotfix

1 answer

Your answer