IronPdf on Windows: "Error while deploying Pdfium" (IronPdf.Slim, Missing Visual C++ Redistributable)

Overview

IronPdf.Slim loads a native library, IronPdfInterop.dll, which depends on the Microsoft Visual C++ v14 Redistributable (x64). If the redistributable is not installed on the server, Windows cannot load the DLL even though the file is present. The deployment then fails with IronSoftwareDeploymentException: Error while deploying Pdfium for IronPdf. Installing the x64 Visual C++ v14 Redistributable fixes the error.

Environment

OS: Windows 11, Windows Server 2022
Hosting: Console app, x64 native deployment
Language/Runtime: C#, .NET 10

Version Metadata

Version found: 2026.9.2
Version resolved: N/A

Cause

The deployed Windows environment was missing the Microsoft Visual C++ v14 Redistributable (x64). NuGet connectivity, package download, and extraction all succeeded, and IronPdfInterop.dll was present. However, Kernel32 could not load the DLL and reported "The specified module could not be found." This message means one of the DLL's own native dependencies was missing. The DLL file itself was present. No product code fix was needed.

Solution

Recommended: Install the Microsoft Visual C++ v14 Redistributable (x64) on the affected server. Then restart the application. The customer confirmed that this step alone resolved the issue.
Make sure the application is published and run as x64. This is an additional deployment check, and it was not separately confirmed as necessary.