I could convert tons of image. But It suddenly stop working. It says

2021-08-14 01:46:37: Can't open input file
2021-08-14 01:46:37: guetzli_windows_x86-64.exe --verbose --quality 90 --nomemlimit 'C:**.jpg' 'C:**_guetzli.jpg'
2021-08-14 01:46:37: Finished with 1

How can I solve this? I need to use this program :(