Uploading to domain-api/add-content can fail in standard setup, as the code expects directories
to be there that aren't:

[Host Controller] 09:52:11,867 ERROR [org.jboss.as.domain.http.api] (pool-2-thread-9) Unexpected error executing deployment upload request: java.io.IOException: No such file or directory
[Host Controller] at java.io.UnixFileSystem.createFileExclusively(Native Method) [:1.6.0_24]
[Host Controller] at java.io.File.checkAndCreate(File.java:1704) [:1.6.0_24]
[Host Controller] at java.io.File.createTempFile(File.java:1792) [:1.6.0_24]
[Host Controller] at org.jboss.as.domain.http.server.DomainHttpServer.extractPostContent(DomainHttpServer.java:240)
[Host Controller] at org.jboss.as.domain.http.server.DomainHttpServer.processUploadRequest(DomainHttpServer.java:123)
[Host Controller] at org.jboss.as.domain.http.server.DomainHttpServer.handle(DomainHttpServer.java:105)

Debugging into it shows

Server tmp dir is /devel/jbas7/jboss-as/build/target/jboss-7.0.0.Beta3-SNAPSHOT/domain/tmp/uploads

where domain/tmp and domain/tmp/uploads does not exist.

This is because the constructor of DomainHttpServer tries to create tmp/uploads, but fails to check if tmp/ already exists (and also ignores the information that creation of tmp/uploads failed).