Problem with compiling Quartus project: Working project is not working any more

Hi all,

I am facing a problem that is not going away in any way.

The problem is when ever I compile my design it gives the following error:

Can't place 37 pins with 2.5 V I/O standard because Fitter has only 32 such free pins available for general purpose I/O placement.

Well, I have changed few banks to other voltages. Then it begins to complain about other voltages, the same way.

I am following a tutorial and using their ready made .csv file for pin assignment(importing .csv file).

This project involves creation of schematic and generation of a Qsys system and then placing the symbol of Qsys system(NIOS II processor) in the schematic.

It worked very fine for few days. Then I changed the Qsys file(according to the part 2 of the lab), and then it stopped working all together(failing to compile since than.

Till part 1 of the lab it was working fine.

So I again started project (lab 1) many times, but even lab 1 is not working now, and same fitter problem. Please see the attached file also.

Should I clean things on system level? if yes, then which files should be deleted or option should be changed.

Any body any guess?