LTSpice error writing to FFT file

Thread Starter


Joined Feb 21, 2012
I'm using LTSpice XV11 (x64) on Windows 10.

Can anyone explain why I have suddenly lost my FFT functionality in LTSpice? When I try to generate an FFT now by the simple method I have always used I get the error message "Trouble writing to FFT file: C:\Program Files\LTC\LTSpiceXV11\Draft1.fft".

The installation location reported in the error message exists and there is no current Draft1.fft file there. There have been no permission issues in the past as this has worked for a year since the latest installation on a new machine.

I'm foxed.


Joined Jun 5, 2013
I have seen this myself.

It is because it is trying to write to the “program files” directory which is protected. Do a “save as” to the schematic to save it iin a user directory, then you will be able to continue.