pdfium.dll locked by IIS Worker Process

[NextAlexM]

Hi there,

Using Pdfium Viewer 2.13.0 (from Nuget) and PdfiumViewer.Native.x86_64.v7-xfa 2.13.0 (from Nuget) in a Web API project but am getting an issue when re-deploying to IIS Express.

The initial run works fine, DLL is copied and loaded fine.
The next time a deployment/run is attempted (In Visual Studio 2017) I get the following error:

Could not copy "pdfium.dll" to "bin\x64\pdfium.dll". Exceeded retry count of 10. Failed. The file is locked by: "IIS Worker Process"

Unable to copy file "pdfium.dll" to "bin\x64\pdfium.dll". The process cannot access the file 'bin\x64\pdfium.dll' because it is being used by another process.

I've seen a few others with similar issues on this GitHub but no real solution.

I believe this is a specific issue with Pdfium Viewer as no other DLL produces the same error.

Killing the "IIS Worker Process" resolves the issue but isn't a practical solution to be doing every time we want to re-run our Web API.

[gauravp-amtrav]

I also had this issue. Ended up having to add a deployment step to restart the website and also recycling the app pool too. Recylcling just the app pool didn't work on its own. However that fix seemed to work for a while but now seeing this issue again. I was hoping didn't have to do a full iisreset everytime. Is there a better solution?