Failed to convert some files

[Soeonye]

Describe the bug
When I try to convert,

Failed to convert some files. Check "error.log"

and there is no information in error.log.

To Reproduce
Steps to reproduce the behavior:

1. Use 'waifu2x-converter-cpp' or 'waifu2x-caffe'
2. Click on 'Prefer GPU' (I don't think any other parameters have any effect)
3. Try to convert
4. See error

Expected behavior
Regular run of the application.

Screenshots
https://imgur.com/NFaOAsT
https://imgur.com/gFYJS1u

Hardware Info (please complete the following information):

• CPU: Intel i5-6500
• RAM: 8GB
• GPU: NVIDIA GTX 750 Ti
• OS: Windows 10
• Converter: waifu2x-converter-cpp, waifu2x-caffe

Additional context
If I use 'Vulkan' or use 'Force CPU only', no error occurs. However, it is inconvenient because the 'Force CPU only' settings are not saved, and I want to know why this is happening.
As a result of checking, the GPU memory is not insufficient at all.

[YukihoAA]

1. did you downloaded fullpack from release page?
2. does your graphic driver is lastest?

I checked cpu option does not saving, it will fixed next version.

[Soeonye]

Yes, I used both the light version and the full version, and confirmed that both had the same problem.
I also used both the latest version and the new version updated today of the graphics driver, but I found the same problem.

[YukihoAA]

try new release!

[Soeonye]

Actually, it still throws an error using the GPU.
However, the error.log comes out normally (though still no reason for the error), and the 'Force CPU only' setting is now saved.
Thanks for your attention to my problem!
I paste the contents of error.log here in case it might be helpful to you:

[Converter]
Current: E:\waifu2x-snowshell_v2.6.1_with_fullpack\waifu2x-converter\waifu2x-converter-cpp.exe
Model:
Option:
WorkDir: E:\waifu2x-snowshell_v2.6.1_with_fullpack\waifu2x-converter

[System]
Cuda: OK
Vulkan: OK
waifu2x-converter-cpp: OK
waifu2x-caffe: OK
waifu2x-vulkan: OK
waifu2x-CUGan: OK
waifu2x-ESRGan: OK

[proc]
0: NVIDIA GeForce GTX 750 Ti (CUDA ): num_core=5

1: NVIDIA GeForce GTX 750 Ti (NVIDIA-GPU): num_core=5

2: Intel(R) Core(TM) i5-6500 CPU @ 3.20GHz (FMA ): num_core=4

Error: E:\waifu2x-snowshell_v2.6.1_with_fullpack\001.jpg