I have an evaluation version of Steema TeeChart running in a method in a .net6 WebApi. The method uses TeeChart to create charts in a PDF document which is then returned as a base64 encoded string to the caller. When running on IIS Express in Visual Studio 2022 it works perfectly. The charts have a watermark over them which is expected. However when I publish to my local IIS server or onto IIS in Azure, the method runs to completion without error but no output is ever returned from the web method.
I have enabled debug tracing for Microsoft and System namespaces in Serilog but no error is produced.
An extract from the end of the trace output on IIS Express looks like this;
2023-12-05 16:14:18.043 +00:00 [INF] Response: StatusCode: 200 Content-Type: application/json; charset=utf-8 Content-Length: 200110 2023-12-05 16:14:18.097 +00:00 [INF] Executed action eLogbookWebServices.Controllers.Api.ReportsController.GetPeerAnalysisReport (eLogbookWebServices) in 9243.3803ms 2023-12-05 16:14:18.098 +00:00 [INF] Executed endpoint 'eLogbookWebServices.Controllers.Api.ReportsController.GetPeerAnalysisReport (eLogbookWebServices)'
The last two lines indicate that the method has completed and the base 64 encoded pdf is returned
On IIS those two lines are never produced. The trace stops at the content-length line.
If I remove the call to the code that uses TeeChart and return null rather than the base64 encoded pdf the method completes as expected on IIS.
My understanding is that the evaluation version of TeeChart will run on IIS and produce charts with a watermark on it. Does anyone know if this is the case? Or is it limited to running only within the Visual Studio environment?
Could you add the key lines of code please, that cause the error (or failed export). Does the failure occur for other export types, to jpg or png for example?