User reports that with CodeMix installed, the projects fail to build because they cannot delete files from the bin folder (Eclipse’s build output folder).
Cleaning the projects also fails. The build works when Eclipse is restarted.

Exception in the log :

Could not delete: bin.
java.nio.file.DirectoryNotEmptyException: bin
at sun.nio.fs.WindowsFileSystemProvider.implDelete(WindowsFileSystemProvider.java:266)
at sun.nio.fs.AbstractFileSystemProvider.deleteIfExists(AbstractFileSystemProvider.java:108)
at java.nio.file.Files.deleteIfExists(Files.java:1165)
at org.eclipse.core.internal.filesystem.local.LocalFile.internalDelete(LocalFile.java:253)
at org.eclipse.core.internal.filesystem.local.LocalFile.delete(LocalFile.java:137)