I've created a batch task foo for a project that did not have any batch tasks before. Then I've added my project name to "Post-build Actions"/"Invoke batch tasks". The dropt down list was empty. Then I've pressed "Save" and openeded the project configuration agian. Now "Post-build Actions"/"Invoke batch tasks" showed "foo" automatically. So things appear to be ok. But when I run the build, I get an error "ERROR: No such task exists: . Perhaps you meant foo". So I open the configuration again, just click on the "Post-build Actions"/"Invoke batch tasks" drow down list and save it. Then things work.