Canon LIDE 300 not seen by Image Capture on macOS Tahoe

If you're hitting the "Cannot communicate with scanner" error with your CanoScan LiDE 400 on macOS Tahoe, here's what's actually going on and a free workaround that doesn't need Canon's software at all.

Why it happens: Canon's IJ Scan Utility Lite is missing a required macOS security entitlement (com.apple.security.automation.apple-events) in its current build. macOS Tahoe enforces this strictly, so the app's internal helper process gets silently blocked by the system — no permission prompt, nothing you can fix in Settings. This is a bug in Canon's app, not your Mac. Canon's own support page doesn't even list Tahoe as a supported OS yet for this model, so a real fix may take a while.

The workaround: Your scanner's USB hardware is fine — the open-source SANE project has supported LiDE 400 since 2019 (genesys backend), completely independent of Canon's broken software. Here's how to get scanning again, with a simple one-click app at the end (no watermarks, no trial limits):

1. Install Homebrew (skip if you already have it — check with brew --version in Terminal):

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

2. Install SANE:

brew install sane-backends

3. Confirm it sees your scanner:

scanimage -L

You should see something like device 'genesys:libusb:...' is a Canon LiDE 400 flatbed scanner.

4. Find the exact path to scanimage (you'll need this for step 6):

which scanimage

(usually /opt/homebrew/bin/scanimage on Apple Silicon, /usr/local/bin/scanimage on Intel)

5. Important — quit any Canon scanner processes first, since they can lock the USB device even in the background:

killall CIJSULAgent
killall "Canon IJ Scan Utility Lite"

Also go to System Settings > General > Login Items & Extensions and turn OFF anything Canon-related, so it doesn't relaunch and block the scanner again.

6. (Optional but nice) Make a simple one-click scanner app:

• Open Script Editor (Spotlight search)
• Paste this in, replacing the scanBin path with what you found in step 4:

applescript

set scanBin to "/opt/homebrew/bin/scanimage"
set desktopFolder to POSIX path of (path to desktop folder)
set timestamp to do shell script "date +%Y%m%d-%H%M%S"

set choices to {"PNG — Small (150 dpi, fast)", "PNG — Medium (300 dpi)", "PNG — Large (600 dpi, best quality)", "PDF — Small (150 dpi, fast)", "PDF — Medium (300 dpi)", "PDF — Large (600 dpi, best quality)"}

set userChoice to choose from list choices with title "Scanner" with prompt "Choose format and quality:" default items {"PNG — Small (150 dpi, fast)"} OK button name "Scan" cancel button name "Cancel"

if userChoice is false then
	return
end if

set selectedText to item 1 of userChoice

if selectedText starts with "PDF" then
	set fileFormat to "pdf"
else
	set fileFormat to "png"
end if

if selectedText contains "150" then
	set dpi to "150"
else if selectedText contains "300" then
	set dpi to "300"
else
	set dpi to "600"
end if

set pngPath to desktopFolder & "scan-" & timestamp & ".png"

display notification "Scanning at " & dpi & " dpi..." with title "Scanner"

try
	do shell script scanBin & " --format=png --resolution " & dpi & " > " & quoted form of pngPath
	
	if fileFormat is "pdf" then
		set finalPath to desktopFolder & "scan-" & timestamp & ".pdf"
		do shell script "sips -s format pdf " & quoted form of pngPath & " --out " & quoted form of finalPath
		do shell script "rm " & quoted form of pngPath
	else
		set finalPath to pngPath
	end if
	
	set answer to display dialog "Done: " & (do shell script "basename " & quoted form of finalPath) buttons {"OK", "Open file"} default button "Open file"
	if button returned of answer is "Open file" then
		do shell script "open " & quoted form of finalPath
	end if
on error errMsg
	display dialog "Error: " & errMsg buttons {"OK"}
end try

• File > Export, set File Format to Application, save it wherever you like (drag it to your Dock for one-click access)
• Double-click, pick your format/quality, hit Scan — done. Files land on your Desktop as scan-<timestamp>.png or .pdf, never overwriting old ones.

Hope this saves someone the hours it took me to track down. Happy to answer questions if you get stuck on any step. still waiting for a official driver , but until that is done this can help you do you basic work !

The Canon LiDE 300 and 400 are both currently supported USB AirPrint devices in macOS 26.5.2. I know, because my LiDE 400 is configured and quite usable with Image Capture, or VueScan Professional. I purposely did not install any software from the accompanying Canon CD.

In System Settings > Printers & Scanners, just remove then re-add the LiDE 300 as an AirPrint device. You shouldn't have to do this (I didn't) between Sequoia and current Tahoe version.

I use a USB-A to USB-C 3.2 dongle between the LiDE 400 and my StarTech USB-C hub.

With AirPrint, Image Capture functionality is what you see is what you get. It is not extensible for custom features.

https://support.apple.com/guide/image-capture/welcome/mac

If you need something that likely even exceeds the Canon IJ utility, then there is VueScan Professional/VueScan Standard Edition. A single purchase is now prohibitively expensive, and I would recommend the annual subscription at $68. Or, without the need for slide/film scanning, you can probably get by with the Standard Edition version of VueScan for less money.

You can trial it for free and there is a PDF user guide. I use VueScan Professional with my LiDE 400, and my Pacific Image Electric PrimeFilm XA Plus slide and film scanner.

Back in 2010, when I originally purchased VueScan Professional, it was $79 single purchase and I have never paid for any upgrade fee since.

I am not affiliated with Hamrick software, nor receive any benefit from them for product mention here. Just a satisfied user with the product and the support when needed.

Logging out and back helps in my case.

That AirPrint search is from this link: https://mfi.apple.com/account/airprint-search

What are you using to bridge the scanner USB-A to USB-C signal? The Apple cable, or one of these? I use a XAOSUN brand version of the latter dongle.

According to Canon website below it should work in Tahoe. If not, ask Canon.

https://www.usa.canon.com/support/p/canoscan-lide-300

Off topic - may i ask - im replacing a soon to be outdated canon mx922 with a ts9521ca, but it doesnt not have the scan resolution of the mx922 so i bought a lide400. BUT, that does not support/ include full function ij scan utility. Is there a way to make what i not have, the full function IJ Utility - i love the different options, etc and have been using it heavily for years, or do i have to find something else?? Tks much!

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