Application crashes on ReportDocument.Close()

I have read other threads about the same issue but unfortunately it didn't help me.

Basically my code is as follows:

Dim rd As New CrystalDecisions.CrystalReports.Engine.ReportDocument<br>rd.Load(txtReportPath.Text)<br>... enumerate the rd.ParameterFields collection ...
rd.Close()<br>

And the application hangs at rd.Close()

The report is completely empty, no database connection, no formulas, no parameters, nothing. Except for one text object to display the word "test".

We are using SAP Crystal Reports runtime engine for .NET Framework (32-bit) 13.0.21.2533. The (test-)application is 32-bit, target framework .NET 4.5.2, and runs on Citrix terminal server / Windows 2012 R2 Standard.

When I run the same test-application on a file server from the same customer it works fine. I have asked the system admin to reinstall the above mentioned Crystal Reports runtime, to no avail.