You will not see the complete toolpath if it is over 500 lines and you are not licensed.
I think updating Mach may help with your spindle speed issue as it seems to have been an on/off issue over the years.
Hood

Hi,
My mach3 is licensed, I have run more that 1500 lines without problem. I will update to see.
Thank you.

Update done and still the same problem. Any ideas?

Thank you

attach your xml and I will see if there is a problem with it.
Hood

I have this two profiles, both do the same problem.

This too

Both of these xml's show that Mach is running in demo mode, so either you do not have your licence in the correct folder or your licence is corrupt.
Hood

I bought this CNC with computer and mach3 installed, the guy told me that he had bought a license for mach3.

 Mach Licenses are owned by the person that purchased them and can not be transferred to another, whether that is with a machine or separately.
Hood