RAS OEM Padding is invalid and cannot be removed

794 Views Last edit Jul 13, 2022 at 03:08 PM 2 rev

We have 3 Servers; 2 Load Balanced Application Servers running an ASP.NET website in IIS7. Let's call these Server A and Server B, and 1 Report Application Server using Crystal Reports Server 2020, OEM (aka RAS OEM or Unmanaged RAS).

The clientSDKOptions file has been setup on both App Servers. The machineKey has been setup in machine.config on both Servers. We are using 'sticky' sessions in Load Balancing. So, we should be setup to share reports between the Servers.

However, if a report is originally loaded by Server A, then when it is reloaded it is directed to Server B, we get a "Padding is invalid and cannot be removed" error.

I've tried tracing with WireShark and I am pretty sure the error is coming from Crystal Reports. The aspx page loads, but is rendered with the error message. So, the Crystal Report Viewer shows a valid page, but it contains the error message only.

Any ideas, please?