Hello,
I’m trying to stack narrowband subs + flats and master dark/bias. Previously I’ve stacked LRGB with no issue, but am failing to stack SHO subs.
The error I get immediately upon clicking GO in the console is as follows:
22:01:49: ━━ Starting pre-processing pipeline ━━
22:01:49: ━━ Phase 1 – Master Bias ━━
22:01:49: Using existing master bias: Master Bias - 150pcs -10c -G125 -O25.fit
22:01:49: ━━ Phase 2 – Master Darks ━━
22:01:49: [2026-06-19] No dark subs – no external folder → skipped
22:01:49: ━━ Phase 3 – Master Flats ━━
22:01:50: Running command: cd
22:01:50: Setting CWD (Current Working Directory) to ‘H:\Siril\Flying Dragon_preproc\session_2026-06-19\flat_H’
22:01:50: Running command: convert
22:01:50: Convert: processing 50 files…
22:01:51: Conversion succeeded, 50 file(s) created for 50 input file(s) (50 image(s) converted, 0 failed)
22:01:51: Execution time: 1.56 s
22:01:52: Running command: calibrate
22:01:52: FITS error: failed to find or open the following file: (ffopen)
22:01:52: FITS error: flat_H_00001.fit
22:01:52: Could not load image 0 from sequence flat_H_
22:01:52: Command execution failed: invalid input sequence.
22:01:52: Running command: cd
22:01:52: Setting CWD (Current Working Directory) to ‘H:\Siril\Flying Dragon’
22:01:52: 
Returned to working directory: H:\Siril\Flying Dragon
22:01:52: _preproc directory removed.
22:01:52: Siril error: Command ‘calibrate’ failed: Sequence not found