moving average filter - unkown signal issue

Thank you for you reply Tricky!

I have attached the project folder, all design files are found in vhd_files. stimulus.vhd contains the input stimuli and testbench.vhd is the top level design file.

I have created a .do file, if you change the path to the project directory and execute it with modelsim will bring up the simulated result.

Thanks a lot for your help!