Bug reports

I set an option GridView->[Return to Grid mode via double-click on single file view]. This is usefull for return to single file view by double click (clasic, left button double click). I use different actions on different mouse buttons, and double-click triggers on a quick press of any buttons, not just the left one (logitech mx master 3 mouse have a few extra buttons)

I have set a shortcut MClick to [select/deselect the current file]. This only works in single file view and does not work in grid view.
 
Also in the grid mode, I use the keyboard shortcut Ctrl+LClick to [select/deselect the current file and move to next] and it seems to be working.
It looks like MClick is not being processed in grid mode

Hi.
There is an issue with DNG files created by Adobe software with DeNoise AI (LrC, ACR) when viewed in FRV.
This DNG files contain original Bayer pattern RAW data as a backup along with denoised linear DNG data.
When viewed in FRV, that original CFA Bayer RAW data is displayed and it looks exactly like original RAW from which this DNG was derived (no denoise at all).

Adobe Camera Raw introduced a new ".acr" sidecar extension with ACR version 14.0 in 2021. This file appears to be a binary file associated with the ACR masking features introduced at in that release. 
Editing a raw file in ACR (for example, launching Photoshop from FRV) will create these files if the user creates masks.  The file is then read  when the file is opened again in ACR or imported into Lightroom.
FRV appears to NOT move the .acr file when it moves the associated raw (and xmp) file to a different folder (including a _Rejected folder).

This problem occurs not only when cleaning with removing the _rejected folder, but also when changes in the folder structure are made from outside the program.
 
How to repeat (checked twice):
1. make a folder [1] with at least 2 photos in it
2. open FRV in [1] and delete one photo (move to _rejected)
3. reopen FRV (it will open in the last folder, i.e., [1], folder _rejected). [1], the _rejected folder already exists, with 1 photo in it)
4. execute Clear _rejected subfolder (check all options, so _rejected subfolder will be removed)

When viewing a single picture in the main windows with thumbnails below and then another program updates the same picture, I want to update the view with the changes, so I right-click and select Reload File(s).
 
This only updates the thumbnail but NOT the main view.  The only way to get the main view to update is to restart FRV.

When navigating my PNG files by pressing right/left arrow keys, I notice the slowness in the latest 2.0.8.2011 MAC version.
I reverted back to 1.7.8 MAC version and the problem was gone. I checked MAC's memory pressure and it showed high memory usage from FastRawViewer.
It's a MacBook Air m2 16GB/512GB machine. 

With all options under Interface -> Selection disabled, I encounter this behavior:
 
Scroll to the bottom of any folder and select the last photo. Hold down shift and press left key, selecting several photos. Let go of shift. Press left twice. Hold down shift and press left twice.
 
Expected Behavior: After letting go of shift key, pressing left twice, and selecting two new photos, I expect only those two photos to be selected.

Happy New Year,
 
In addition to viewing images, I use FastRawViewer as a file organizing tool. When reviewing assets from my phone or cameras, the folders also include videos. I've exposed the MP4 files so that I can include them when moving assets to new folders. If I didn't do this, a folder might appear empty (when there are, in fact, videos from iPhone live photos, or movie files from the most recent import).
 

Originially I thought this was an ACR bug, but now I think its a FRV bug.  Please see the screen shots I posted in the Adobe Community Forum.