At my request, the author of IrfanView has done a lot of work to correct the errors existing in version 4.66.
1. Fixed a bug in viewing heic files. When viewing some heic files, an error occurred in recognizing the file header.
2. Fixed an error in displaying tiff files with an ICC profile.
When the ICC profile was enabled in the IrfanView settings, these files were displayed as a black square.
3. Fixed an error in displaying the number of pages of multi-page tiff files.
These fixes affect the i_viewХХ.exe files and the Lcms.dll, Tools.dll plugins. The author simply added the remaining new versions of plugins to the archive. You can use them or not.
There is also a new plugin PsHost.dll. As the author explained, it improves the display of the black and white theme.