Nios II IDE error

People, not rarely, when I rebuild a project, the following message is displayed in Nios IDE terminal:

Compiling <file_name>.c...

Linking <file_name>.elf...

/cygdrive/d/altera/kits/nios2_60/bin/nios2-gnutools/H-i686-pc-cygwin/bin/../lib/gcc/nios2-elf/3.4.1/../../../../nios2-elf/bin/ld: cannot open output file <file_name>.elf: Permission denied

collect2: ld returned 1 exit status

make: *** [neuron_0.elf] Error 1

Build completed

Till today I&#39;ve just solved the prroblem restaring PC. I&#39;ve just tryied to restart Nios II IDE and/or clean the project, no success though.

Is somebody knows why this error ocurres and how toI can solve it in a better way?

Thanks a lot, people.