did you compile your designfiles/tb into the work lib using vlib and 
vcom?

hi,
yes all files including the testbench are compiled.

Hi supachris,
thx for the hint but the only error line I recieve is the "#Error 
loading design" line and no other output. This is the fact that keeps me 
from investigating further.

I am getting the error "Error Load Design"(Modelsim student version).
I have three modules and all are compiling without errors.
However,the order for one of them (test bench) stays '0' in the left 
window.
Now,while trying to run the three modules,I was getting the error which 
I have specified above.

If the topmodule isn't loadable, try the submodules one by one.

Make sure that your PDF student license is contained in the 
C:\Modeltech_pe_edu_10.0c' directory folder only( i.e. is not contained 
in any subfolders, the 'win32pe_edu' folder in particular!). I tried 
this before and it cured the #Error loading system# for me when it 
appeared!

I hope this will cure some headaches aswell!

Regards,
Sentinel.

Hi,

I just had the same error message myself
and this is how I fixed it

#Error loading design

- Check your license is not in a sub folder especially 'win32pe_edu' in 
the  ModelSim directory

- and then check your "tb" design to see if your "module" and "uut" name 
are one and the same for example mine was

         module tb_ex1_gate();

and
         ex1 uut

This led to the error "#Error loading design" because ModelSim could not 
find it in the libraries, it should have been

         module tb_ex1_gate();

and
         ex1_gate uut

also when the this error appears you can find more detail when you 
scroll up on the Transcript section


I hope all this helps I am using ModelSim PE Student Edition 10.0c

Thanks, Christian. Your input has helped me! Cheers..

hi I have same Error which is error loading design
there is no any problem in my code also the licen. file was downloaded 
in my computer but i dont know the problem that make my modelsim doesnot 
run the code is there any one has the solve thanks

This do not solve my problem...

# Compile of TB_Add1b.vhd was successful.
# Compile of Add1b.vhd was successful.
# Compile of config_Add1b.vhd was successful.
# 3 compiles, 0 failed with no errors.

ModelSim > vsim -voptargs=+acc -t ns work.cfg_test
# vsim -voptargs=+acc -t ns work.cfg_test
# Error loading design

Kel wrote:
> hi,
> yes all files including the testbench are compiled.

Loding...

module Alsu8bit (a,b,cin,s3,s2,s1,s0,z);
     input [7:0]a,b;
     input cin,s3,s2,s1,s0;
output [7:0]z;
wire cout;
 wire [7:0] au,lu,shr,shl;
au8bit   au0 (a[7:0],b[7:0],cin,s1,s0,cout,au[7:0]);
lu8bit   lu0(a[7:0],b[7:0],s1,s0,lu[7:0]);
shru8bit shr0 (a[7:0],1'b1,s1,s0,shr[7:0]);
shlu8bit shl0 (a[7:0],1'b1,s1,s0,shl[7:0]);
mux8bit  alsu (au[7:0],lu[7:0],shr[7:0],shl[7:0],s3,s2,z[7:0]);
endmodule

hi,
i got the same error and i saved the license file in 
C:\Modeltech_pe_edu_10.4a . it would be very helpful if anybody let me 
know wht should i do to remove this error

Hello. This is my code of full subtractor using 2 half subtractors. No 
error in compiling. but there is this error will simulating the program:


Port w and d are not found in the connection module.



module hs(diff,borrow,a,b);
  output diff,borrow;
  input a,b;
  assign diff= a^b;
  assign borrow= ~a&b;
endmodule
module fs(diff,borrow,a,b,cin);
  output diff,borrow;
  input a,b,cin;
  wire [1:0]w,d;
  hs a1(.w(w[0]),.a(a),.d(d[0]),.b(b));
  hs a2(.a(d[0]),.d(d[1]),.b(cin),.w(w[1]));
  assign diff=d[1];
  assign borrow= w[0] | w[1];
endmodule


I will be obliged if you could help.

Here's another thought....

I had this problem after moving a simulation folder containing all my 
verilog and project files.  After opening the project file (*.mpf) in a 
text editor, I found all verilog files were described with absolut path 
names, NOT relative path names. A simple find & replace to correct the 
path would fix it!

Joseph wrote:
> Here's another thought....
>
> I had this problem after moving a simulation folder containing all my
> verilog and project files.  After opening the project file (*.mpf) in a
> text editor, I found all verilog files were described with absolut path
> names, NOT relative path names. A simple find & replace to correct the
> path would fix it!

This is the correct fix for most of these errors. It's another one of 
ModelSim's wonderful "quirks", of which there seem to be an infinite 
amount!

* Error: (vsim-3053) C:/Users/Uzma/Desktop/fedup/fsm_tb.v(9): Illegal 
output or inout port connection for "port 'out'".
#

Plz help as i dont understand the meaning of this error.. output port 
has been clearly identified but still its not loading the file...

// My FSM TB Code
module fsm_tb;

reg clk,rst;

reg din;

reg out;

fsm MUT(din,rst,clk,.out(out));

initial

clk<=1;

always

#5 clk <=  ~(clk);

//Set occurance of sequence
initial
begin
@(posedge clk);     din <= 1'b1 ;
@(posedge clk);     din <= 1'b0 ;
@(posedge clk);     din <= 1'b0 ;
@(posedge clk);     din <= 1'b1 ;
@(posedge clk);     din <= 1'b1 ;
@(posedge clk);     din <= 1'b0 ;
@(posedge clk);     din <= 1'b1 ;
@(posedge clk);     din <= 1'b0 ;
@(posedge clk);     din <= 1'b1 ;

end

endmodule

1

$ vlog fsm_tb.v

2

Model Technology ModelSim SE-64 vlog 10.3d Compiler 2014.10 Oct  7 2014

3

Start time: 12:00:36 on Nov 21,2016

4

vlog fsm_tb.v

5

-- Compiling module fsm_tb

6

** Error: fsm_tb.v(10): near ".": syntax error, unexpected '.', expecting ')'

7

End time: 12:00:36 on Nov 21,2016, Elapsed time: 0:00:00

8

Errors: 1, Warnings: 0

After changing ".out(out)" to "my_out(out)", I got the following output:

1

$ vlog fsm_tb.v

2

Model Technology ModelSim SE-64 vlog 10.3d Compiler 2014.10 Oct  7 2014

3

Start time: 12:01:41 on Nov 21,2016

4

vlog fsm_tb.v

5

-- Compiling module fsm_tb

6

7

Top level modules:

8

        fsm_tb

9

End time: 12:01:41 on Nov 21,2016, Elapsed time: 0:00:00

10

Errors: 0, Warnings: 0

Duke

It worked for me

************************************************************************ 
*
Author: Sentinel (Guest)
Posted on: 2011-10-06 17:15
Make sure that your PDF student license is contained in the
C:\Modeltech_pe_edu_10.0c' directory folder only( i.e. is not contained
in any subfolders, the 'win32pe_edu' folder in particular!). I tried
this before and it cured the #Error loading system# for me when it
appeared!

I hope this will cure some headaches aswell!

Regards,
Sentinel.
************************************************************************ 
*
Sentinel

YOU ARE A GENIUS !
COOL!

thanks, it was very helpful!

Maybe somebody already mentioned it but just to be sure, after you've 
saved the license file in the right directory as described in previous 
posts, close ModelSim and then try again to simulate because otherwise 
the error won't disappear

please help don't know what to do

Error loading design (Modelsim student version)

Thanks ,it works

this method works..

i am keep on getting error loading design error after when i click on 
simulate
i have tried some things
but i was not able to correct
could someone explain it briefly how can i solve this problem

My code has been compiled successfully but on simulating the following 
error is shown. Please help in rectifying the error.

vsim -gui work.half_adder
# vsim
# Start time: 21:24:16 on Oct 13,2018
# Error loading design

Here are the basic steps for using modelsim from command line:

1

1. Create library (working directory for modelsim):

2

$ vlib work

3

4

2. Compile design:

5

$ vcom design.vhd

6

Start time: 11:18:20 on Oct 16,2018

7

vcom design.vhd

8

Model Technology ModelSim SE-64 vcom 10.6c Compiler 2017.07 Jul 26 2017

9

-- Loading package STANDARD

10

-- Loading package TEXTIO

11

-- Loading package std_logic_1164

12

-- Compiling entity design

13

-- Compiling architecture rtl of design

14

End time: 11:18:20 on Oct 16,2018, Elapsed time: 0:00:00

15

Errors: 0, Warnings: 0

16

17

3. Compile testbench:

18

$ vcom testbench.vhd

19

Start time: 11:19:23 on Oct 16,2018

20

vcom testbench.vhd

21

Model Technology ModelSim SE-64 vcom 10.6c Compiler 2017.07 Jul 26 2017

22

-- Loading package STANDARD

23

-- Loading package TEXTIO

24

-- Loading package std_logic_1164

25

-- Compiling entity testbench

26

-- Compiling architecture testbench of testbench

27

End time: 11:19:23 on Oct 16,2018, Elapsed time: 0:00:00

28

Errors: 0, Warnings: 0

29

30

4. Start simulator:

31

$ vsim -gui testbench

32

33

5. Add some signals to view:

34

VSIM 1> add wave *

35

36

6. Run simulator for a specified time:

37

VSIM 2> run 1 ms

38

39

7. Zoom the wave window:

40

VSIM 3> wave zoom full

41

# {0 ps} {1050 us}

Duke

plz any aide

any aide

help with the error massage: error loading design

Thanks guys, matching these names and then redefining in the simulation 
file settings solved this problem for me.

Checks: 1.student license must be in the same folder of ModelSim
        2.If not cut and paste it.
        3.run the simulation
If you have done above things but still getting same.Then
        Uninstall ModelSim and again reinstall it.

You were SOOOO right about the license path! Thank you so much!

My work library will not work proper.when i will compile it will add 
another work library in compile and show the work library empty.Anyone 
can tell me the problem.

I had the same problem for almost 2 months now. This is how i solved it:

For those trying gate level simulation and using a sdf file along with 
it, you must also compile the sdf file. But it not like compiling any 
other file. You must use the command sdfcom. Also when using this 
command, you must also specify the sdo file name as input, and a new 
file name that will be used as output file. So the syntax goes like:

sdfcom [ options ] source-file output-file

This might help some people.
I am using Modelsim FPGA Starter version 10.5b

Thanx

hi,
i am even getting same erroe and in the blue line it's written
( Error: (vsim-3173) Entity 
'C:/Modeltech_pe_edu_10.4a/CourseraFPGA/Course2/AAC2M1P1/work.comparator 
2'  has no architecture)
Please suggest what should i do.

# vsim
# Start time: 11:53:42 on Oct 20,2020
# Error loading design

this is the error that keeps showing when i try to simulate my codes
module bufif_notif_gates (output c,d, input a, b);
bufif1 (c, a, b);
notif1 (d, a, b);
endmodule
module bufif_notif_gates_tb;
  reg tb_a, tb_b;
  wire tb_c, tb_d;
  bufif_notif_gates_tb Instance0 (tb_c, tb_d, tb_a, tb_b);
  initial begin
    tb_a = 0; tb_b = 0;
 #1 tb_a = 0; tb_b = 1;
 #1 tb_a = 1; tb_b = 0;
 #1 tb_a = 1; tb_b = 1;
  end
  initial begin
    $monitor ("T=%t| a=%b |b=%b| c(bufif)=%b |d(notif)=%b", $time, tb_a, 
tb_b, tb_c, tb_d);
  end
endmodule

this is my code. i don't know how to fix this :(

You need three steps to simulate in modelsim:

1. create library:
vlib work

2. compile all design files (and the testbench!) into the library (work 
is the default):
vlog my_design.v
vlog my_testbench.v

3. start simulation:
vsim -gui my_testbench

That's it.
Duke

how to fix this prblm?


 //
# vsim -gui
# Start time: 00:25:07 on Dec 06,2020
# Loading work.tb_1101moore_74
# ** Error: (vsim-3033) C:/Modeltech_pe_edu_10.4a/examples/TB_310.v(13): 
Instantiation of 'moore1101' failed. The design unit was not found.
#    Time: 0 ns  Iteration: 0  Instance: /tb_1101moore_74 File: 
C:/Modeltech_pe_edu_10.4a/examples/TB_310.v
#         Searched libraries:
#             C:/Modeltech_pe_edu_10.4a/examples/work
# Error loading design
vlog -reportprogress 300 -work work 
C:/Modeltech_pe_edu_10.4a/examples/TB_310.v
# Model Technology ModelSim PE Student Edition vlog 10.4a Compiler 
2015.03 Apr  7 2015
# Start time: 00:27:50 on Dec 06,2020
# vlog -reportprogress 300 -work work 
C:/Modeltech_pe_edu_10.4a/examples/TB_310.v
# -- Compiling module tb_1101moore_74
#
# Top level modules:
#   tb_1101moore_74
# End time: 00:27:50 on Dec 06,2020, Elapsed time: 0:00:00
# Errors: 0, Warnings: 0

this is my test bench

when i complile it was like this

vlog -work work -L mtiAvm -L mtiRnm -L mtiOvm -L mtiUvm -L mtiUPF -L 
infact -O0 C:/Modeltech_pe_edu_10.4a/examples/TB_310.v
# Model Technology ModelSim PE Student Edition vlog 10.4a Compiler 
2015.03 Apr  7 2015
# Start time: 14:53:12 on Dec 07,2020
# vlog -reportprogress 300 -work work -L mtiAvm -L mtiRnm -L mtiOvm -L 
mtiUvm -L mtiUPF -L infact -O0 
C:/Modeltech_pe_edu_10.4a/examples/TB_310.v
# -- Compiling module tb_moore1101_74
#
# Top level modules:
#   tb_moore1101_74
# End time: 14:53:12 on Dec 07,2020, Elapsed time: 0:00:00
# Errors: 0, Warnings: 0

Did you have compile moore1101.v also?

Duke

Paulpraveen P. wrote:
> Damm even I am having a similar kind of issue,
New Problem -> new question.
And without specific and detailed error description only people with a 
working crystal ball can help.

Duke

Paulpraveen P. wrote:
> I am really frustrated, can anyone of
> you here help me resolve this issue, I am very much tired now.

As pointed out in this old posting: 
https://embdev.net/topic/error-loading-design-modelsim-student-version#6511390
the cause of the error is "Not all required source files are compiled" .

Also check, if all working libraries are created and active (see command 
'vlib' and 'vmap').

Rahul P. wrote:
> I have three modules and all are compiling without errors.

> Now,while trying to run the three modules,I was getting the error which
> I have specified above.

Again, check library references ('use'-clause, instance-component 
references) as described above.