MikeMon

I resolved the problem by assigning Connected:= False to the TFDConnection during design-time on the Datasnap Server TDataModule and changing it to Connected:= True in the OnCreate method of the TDataModule. I'm not sure if it's really a bug, but that's how I resolved it.

Thank you for your help @Dmitry Arefiev.

How would I do that?

Hi Dmitry

Thank you for your answer.

I know that the REST server is producing the error. But the same client with not a single change in code working with no errors compiled with Delphi 10.1.2, is getting this error compiled with Delphi 10.2.1 and above.

Moreover, I checked the interbase log on the REST server and there are no errors.

Hi

I've been having problems with REST client calls on Delphi Rio 10.3.1. The problem actually started with Delphi Tokyo 10.2.1. Everything worked perfectly with Delphi Berlin 10.1.2.

Not always, but quite often, I'm getting a TDSRestProtocolException exception on the client (which is running on windows) for the same REST call. The message is "HTTP/1.1 500 Internal Server Error" and the ResponseText is {"error":"[firedac][phys][ib]unavailable database"}.

Has anyone come across this problem, or has a solution for it?

Thank you in advance