LTspice
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LTspice® is a powerful, fast, and free SPICE simulator software, schematic capture and waveform viewer with enhancements and models for improving the simulation...
LTspice on Analog.com
This is a highly unlikely simulation situation, and hardly needs fixing.
I swapped between two current sources, using a short circuit across the current source that was momentarily not wanted. Then when the .NOISE command was used, but incorrectly pointing to the short circuited current source, LTSpice crashed. If the same thing is done with voltage sources + series resistors, the .NOISE output doesn't crash and gives zero noise, which is the expected result.
