Exception GetData: Error reading parameter aTableRequestInfoArray

The full exception text:

An exception was raised on the server: Error reading parameter aTableRequestInfoArray: Unexpected class found in stream; class “TableRequestInfo” does not descend from “TableRequestInfo”.

I am using Delphi XE2 with RODA

This happens when I open a datatable. I have been upgrading an older project from D2007.
I have tried creating a simple client app, this gives the same error, so this must be something serverside.

Anyone know of anything, regarding this error. Thanks.

We couldn’t reproduce it on these versions. Can you send us a small testcase which reproduces this error?

I will try to narrow it down into a test case.

What I have found out, is that if I call a service that is a part of the server host EXE, the call works fine, and I receive data.

If I create a Hydra DLL service plugin, and call the GetData through there, I receive the exception.

I will have to try and create a new Hydra DLL project from scratch, and see if it goes away, or when the exception starts showing up.

Please, look at the attached example. Here we use Hydra DLL plugin and GetData

Thank you for the example. I will check it out.

I think I have found the cause of this. My Hydra DLL project was missing some entries in the runtime packages section. DataAbstract_Core_D16 etc.

So now my upgraded project is up and running again.

FYI - I have hit this issue when using a custom Delphi RO/DA CGI Server. (e.g. the TargetURI is http://server/cgi-bin/myserver.exe/bin)

I do not use Hydra or runtime packages & I’ve not encountered this until recently.

RO/DA v10.0.0.1481
Delphi 10.3


are your client and server compiled from the same sources?
what message (bin, soap, json, etc) were used?

i) Yes compiled from the same source.

I also have a Win Service/App Server which is compiled from the same source (apart from the ServerDataModule for the service and a WebDataModule for the CGI Exe)

The service based server is working fine. Just the CGI Exe causing a problem.

To clarify, I have not directly touched the source code of the CGI Exe (i.e. the WebDataModule) in a long while as all my changes are done in the Windows Service/App Server project - of course the CGI Exe shares all the service implementations.

ii) Bin message, with AES envelope.

The error message I get is exactly as above with the following added on: happens during read field 'item'

Thanks for any help you can provide - the CGI Exe is still mission critical :slight_smile:


Can you create a simple testcase that reproduces this behavior, pls?
you can drop email to support@ for keeping privacy.

Could I send the actual project?

I can include the DDL of SQL Server database, but it errors during login so it’s not even getting that far so you may not need it.


yes, you can,
pls clean up it from 3rd party components if they are used.

this project should reproduce ... happens during read field 'item' exception

I don’t think there’s any 3rd party code on the server end… I’ll have a check though.

If you login with any user/pass combination it will attempt to open the users table and that’s where the error occurrs - so it doesn’t matter if you have right or wrong authentication details.

Yes, confirmed, this is the project that generates the error:

Unexpected class found in stream; class “TableRequestInfo” does not descend from “TableRequestInfo” happens during read field 'item'

Sent email now. THanks