RTL simulation on Quartus II

Dear all,

I am getting the following error messages every time I run RTL simulation from Quartus II software:

# -- Loading package STD_LOGIC_UNSIGNED# ** Error: (vcom-11) Could not find altera.alt_dspbuilder_package.# ** Error: C:/Users/nawad/Desktop/without_Detection/JustEqualiser/db/alt_dspbuilder_clock_gnf343oquj.vhd(7): (vcom-1195) Cannot find expanded name "altera.alt_dspbuilder_package".# ** Error: C:/Users/nawad/Desktop/without_Detection/JustEqualiser/db/alt_dspbuilder_clock_gnf343oquj.vhd(7): Unknown expanded name.# -- Loading package LPM_COMPONENTS# ** Error: C:/Users/nawad/Desktop/without_Detection/JustEqualiser/db/alt_dspbuilder_clock_gnf343oquj.vhd(11): VHDL Compiler exiting# ** Error: c:/altera/11.1/modelsim_ase/win32aloem/vcom failed.# Error in macro ./FPGA_design_run_msim_rtl_vhdl.do line 9# c:/altera/11.1/modelsim_ase/win32aloem/vcom failed.# while executing

However, ModelSim simulator result was correct.

Any help would be very appreciated .

Regards,

Nadia