First of all let me point out that I am not sure if what you will read below will help you or not. I just thought I'd share some thoughts since no one else has replied to this question yet.
I know of two reasons which cause "Class not registered" error.
Reason 1:
You are using an ActiveX or other COM object which is not registered in the computer you
run your program.
Reason 2:
You or the components you use are trying to load a delphi object from a stream and that
objects delphi class is not registered by default in your program.
I think in your case its probably "Reason 1". I have never used DATASNAP so i can NOT be
sure. I searched a little on the internet for you because I found it interesting to learn
about and it appears that DATASNAP server side requires that you deploy "MIDAS.DLL" on the
server machine and also on the Client machine (unless you use MidasLib unit in which case
you would not need it in the client machine)[see also Ref 1 below]. I think you will need
Use regsvr32.exe to register Midas.DLL as it contains COM objects (see also Ref 2,3 and 4).
If it is "reason 2" then you would typically see a message "[ClassName] class is not
registered" which would tell you the class you will need to register. And to register it
you can add the following code at the begining of your program :
RegisterClass(ClassName)
Web References:
[1]
[2]
read/fc5b3d7e7bd8fa6f/5e345321cd5d9e0b%235e345321cd5d9e0b
[3]
read/938e83c341c9f2ff/8fcc266ed9f1f533%238fcc266ed9f1f533
[4]
d/117c37037275bd36/133839f1a3b839c3%23133839f1a3b839c3
I hope the above will help you or at the very least i hope it wont cause more confusion.
Good luck