Dear Mr. Torben,
Thank you for your response. I didn't know about pfsmerge.exe utility program and about that feature from Mike11 Network Editor called 'Number Points Consecutively'.
In fact, the first time I didn't do everything manually, I created a small program which adds an integer to all points number and after I combined all the elements into one file. So, I took care to avoid the overlaping of the numbering of internal points. Finaly, the network file worked very well. There was no problem with the network file itself, the problem occured when I tried to run the simulation file.
Anyway, after your message, I tried to start from the original files and I followed the steps you described above. The result is that the pfsmerge.exe gives the next message:
"
Loading xx.nwk11 ...
Error when opening xx.nwk11
Program Halt 1
"
So, thank you very much for your answer which responded perfectly to the third question, but I think I still have the first two questions unanswered:
1) Did you encounter this error: "Access violation at adress .... in module 'mike11.exe'. Read of address ...." ?
2) What exactly those processes do: a) "Allocate and assign grid" and "Allocate node cross sections" ?
Thanks and Regards,
Aurelian