In the Nios® II IDE for version 7.2 SP1 & SP2, in the Problems tab, the following warning can appear: "Invalid project path: Missing project folder or file: \altera.components\bin for Output path."
This warning can be reproduced by creating a user specified workspace location.
This warning can be safely ignored. This non-existent folder is referenced on purpose as a means of accelerating the C/C indexer feature of the Nios II IDE. This prevents unnecessary searching and indexing of all the binary files under the nios2eds installation directory.