Does anyone have Navision 4.0 Hotfix 891518

Hello and welcome,

I did some research, but didn't find anything on that hotfix, and I have only 4.0 SP1 and 4.0 SP3 in my archive.

From the following post, I understand that the update you seek was applied on 4.0 SP2:
http://www.waldo.be/dynamics-nav/platform-updates/dynamics-nav-3-70-5-0sp1/

I don't think we can find the changes of that particular hotfix and the fixes you must do.
Maybe you could transfer your customer to the "newer" version of 4.0 SP2 or even SP3.

You can get it from:
https://mibuso.com/downloads/microsoft-business-solutions-navision-w1-4.0-sp2

Also, the database/dev. toolkit for 4.0 SP2 is here:
https://mbs.microsoft.com/customersource/Global/NAV/downloads/service-packs/MicrosoftBusinessSolutionsNavision40SP2#overview

The 4.0 SP3 version can be found here:
https://mibuso.com/downloads/microsoft-dynamics-nav-w1-4.0-sp3

I hope the above to prove useful to you...

I have searched high and low to find it... No luck...

But, I have found an old article of some1 with the "same" problem.

MS suggested that he would do a technical upgrade (only convert databases to 4.0 SP1 and use the 4.0 SP1 clients and nodbc.dll).

That way, you have the objects from version 4.0 and apps/dlls from 4.0 SP1.

The article is here:
https://microsoft.public.navision.narkive.com/LWAYE8z2/nodbc-with-nav-4-0-and-hotfixed