If you are developing custom pipeline components, you’ve likely encountered the “Access Denied” or “Cannot copy file” error during a build. This problem occurs frequently when we try to deploy pipeline components (copying the DLL to the folder C:\Program Files\Microsoft BizTalk Server …\Pipeline Components). The message usually looks like this:
“cannot copy “custom pipeline component” as the earlier is in use”
📝 One-Minute Brief
When deploying custom BizTalk pipeline components, you may encounter an error stating the file cannot be copied because it is in use. This happens because the Visual Studio Pipeline Designer or a BizTalk Host Instance has already loaded the DLL into memory. To resolve this, you must close all instances of the Pipeline Designer in Visual Studio and, if necessary, restart the BizTalk Host Instance (or the isolated host if using IIS) to release the file lock.
This happens because BizTalk or Visual Studio is “too helpful”—it has loaded your component to use it, and Windows won’t let you overwrite a file that is currently mapped in memory.
Cause
- Visual Studio has a lock on the file in order to show the pipeline components in the toolbox.
Or
- Some BizTalk process is running the BizTalk host and has a lock on the file.
Solution 1
- Close Visual Studio and restart the host instance to make sure the pipeline component (DLL) gets released.
- And then deploy the pipeline component.
Solution 2
- Rename the file (it is much faster).
- Restart host instance
- Deploy pipeline component
- And then delete the old DLLs
