All of the sudden we started getting the following exception on the site:

The specified module could not be found.
(Exception from HRESULT: 0x8007007E)

Not one of Microsoft’s more useful error messages, to be true and googling for that error returns so many diverse topics that they were completely useless.

So after a bit of troubleshooting, we came to the following solution tips. These should work for both C# and VB and any other .NET language. Tested on Windows 2003 and Windows Server 2008.

Make sure your webserver is 32-bit

PDFLib for .NET does not support 64-bit servers. In theory you could run your IIS worker processes in 32-bit on a 64-bit OS, but I leave that as an exercise to the reader.

Make sure you have .NET 1.1 installed

Because pdflib_dotnet.dll is built on 1.1 and you will have this installed on your development box, you will never think about this for your prod/staging servers. If you already have IIS installed before you run the 1.1 installer, don’t forget to register it with IIS:

C:\Windows\Microsoft.NET\Framework\v1.1.xxxxx\aspnet_regiis.exe -ir


Put the MSVCR71.DLL into your web bin directory

On your development machine (or wherever you have PDFLib actually installed) the msvcr71.dll will be in C:\Program Files\PDFlib\PDFlib 32-bit 7.0.3\dotNET\bin or thereabouts. Drop that into your website bin directory on the server.

UPDATE: You may also need to place this dll into the C:\Windows\System32 folder on a dedicated server.

Reboot, then check it out.

Taste the sweet goodness of success.

PDFLib produces a great end product (and it should for that much caaaassssshh). But it has many weird cases. Probably because it seems that the .NET version is just a simple crappy wrapper on the C library. Oh well. It’s still the best thing on the market to separate your developers from your designers.