Scanner is on but get message "unable to open Twain source"

SOURCE: Lock Switch and IF cable

Mine was doing the same thing. When I get on the program, before I click "acquire" to preview and scan, I click OFF the toolbox and then everything seems to be okay and I can go ahead and scan.

SOURCE: Scanner has stopped working

When I had the cable that came with the printer connected to the scanner, and the cable that came with the scanner connected to the printer, the scanner didn't work.

Changing the cables changed everything.

SOURCE: canon scanner

TWAIN is the type of scanner driver that is used for this scanner. It is probably the most common type of scanning driver.

Did you install Toolbox? Not sure? Assuming this is Windows, click Start, All Programs, Canon. Look for open CanoScan Toolbox (4.9 I think). Once this is open, click the 'Settings' button. There should be a drop-down menu for 'Select Scanner'. Make sure this shows the CanoScan LiDE 25. If that scanner is not listed, then the scanner driver is not being seen or may not be installed.

Once it has been verified that the LiDE 25 is selected, click OK. Next, click the 'Save' button. Check the box for 'Display the Scanner Driver'. Now click the 'Scan' button at the bottom.
The next window that pops up should be ScanGear. If this happens, then everything is installed and the scanner is being detected properly. Attempt to scan or preview.

If there was a particular application you were trying to use and you are still having issues with it, please give those details.

SOURCE: Unable to select TWAIN source

Reinstall the ScanGear driver and Toolbox.

http://consumer.usa.canon.com/ir/controller?act=DownloadDetailAct&fcategoryid=351&modelid=6624

SOURCE: Error message

Hi toolpusher

Try going to CanoScan Toolbox > Settings and reset the 'defaults' button at bottom... this will restore factory settings and hopefully fix your problem... The other error message you can expect to get is "unable to scan - insufficent memory, check your **** space' (or something similar)... same fix works for both! ...Have had both messages on mine, sounds like a semi-regular conflict on some sort, but seems to be easily fixed. Good luck :-)