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Urgent: Reverse Client Update to 6.5?!

Former Member
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We have two SAP servers for development. One server has only databases in version 6.20.36, the other one has only 6.5 databases.

Since I am bound to work with both versions of SAP Business One, I have tried to install a 6.5 client and a 6.2 client on my developing machine.

This definitely does not work. So I tried to reverse all and reinstall the SBO 6.2 client plus DIAPI and UIAPI.

When trying to connect via UIAPI I now receive the following error in .NET:

"System.InvalidCastException: QueryInterface for interface SAPbouiCOM.ISboGuiApi failed"

For some reason the references to the newly installed com objects do not work. Are there any hints on how to revert the installation of the 6.5 client?

Thank you in advance,

Lutz Morrien

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Answers (4)

Answers (4)

Former Member
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Indeed, I just found SAP note <b>693922 Upgrating SDK versions</b> and read it.

It says that downgrading from client version 6.5 to 6.20.36 might take some time... I spent a <b>long</b> time on this.

Sadly, the note does not tell how to downgrade ;(

This whole issue makes me afraid of more versions to come. Do we need a separate workstation and a separate server for each version in order to develop?

By the way, the workstation seems to run allright again. After installing and uninstalling one last time - plus cleaning the registry.

I hope this condition will last until tomorrow.

Thanks, Lutz

Former Member
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Hi Lutz,

as far as I don't have administrative rights on my machine , I can't give you a direct link. I just remember, that I had a similar problem and it was solved after deleting all corresponding registry entries. Just search the registry for "SAP" and "SBO" - then you should be able to find it. Did you also check the database, if the version number is still the correct one, or if the client overwrote it with a false one?

I'm pretty sure, that I've seen a SAP note adressing this topic also...



Former Member
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Hi Dierk,

I uninstalled the client plus UIAPI and DIAPI. However, after uninstalling all, deleting all folders and removing all entries I could find, there was still a reference to UIAPI 6.5 left in the system.

Reinstalling version 6.20 with all APIs did not solve the problem. I could not register the neccessary com components neither with vb6 nor with .Net.

Any hints to specific registry entries to delete?

The different version clients do seem to uninstall incompletely. I guess I'll have to redo my whole workstation, since I cannot find the problem.

Any other ideas?

Thanks Lutz Morrien

Former Member
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in my opinion it wouldn't have been necessary to reverse all and reinstall the client. Normally (and this is also my experience) when connecting to a SBO server, the client should recognize the version and up- or downgrade automatically.

But this is no convenient way of working, so normally I use one local client for one version and a citrix server with another client for another version. If the authorizationpolitics in your company allow you to get a remote connection to the SBO server, you can work with a local (on server) client installation.

So there are many ways to handle this and regularly up- and downgrading surely is the worst. The best - installation of two clients - doesn't work (as you recognize).

So as a next step I would advise you to deinstall all client applications and check also the registry (!!!) for old entries. Then you should reinstall some client (doesn't matter what version) and connect to the server.

Then it should work again.