When used as Lightroom Classic plugins, DeNoise AI 2.3.4 and Sharpen AI 2.2.1 cannot open any file when at least one Japanese character is used somewhere in the full path (doesn’t matter if it’s file or folder name). Other LR plugins on the same machine (old Nik collection from google days) work fine.
No screen shot here (I’m not allowed to upload images?), but I get “Unknown Error” “Could not open image. Please contact support with the image attached if the issue continues.” dialog box. The main DeNoise AI (or Sharpen AI) window in the background shows “Error: Image Does Not Exist”. When the file name (not folder name) has Japanese characters, the DeNoise AI main window shows the file name with each Japanese character replaced with a “?”.
The exact same file in the same folder can be opened when Denoise AI and Sharpen AI are used as stand-alone apps. File -> Open Images as well as drag and drop work.