Chrome OS Scan app returns Couldn't complete scan

[Kowalik]

The Chrome OS scan app cannot find the scanner, with the following message.

Couldn't complete scan
There's an issue communicating with the scanner. Check the network or USB connection and try again..

This problem was concurrent with a printer problem (printer unreachable), which I have been able to fix by removing the printer, adding it, and restarting the Chromebook.

The Chrome OS scan app shows the printer as a USB connection, but when I click on scan I get the above message.

My router, a tp-link deco, does not have a WPS button. I do not know of any other way to connect the printer to Wi-Fi.

The printer does not have a display panel or any ports aside from the (dedicated?) USB port.

On my Android phone Mopria scan identifies the scanner as Wi-Fi direct but cannot connect to it.

Thanks in advance for any help or suggestions.

[Kowalik]

I found out how to connect the printer to the router. It appeared to work - the Wifi button is solid

BUT

Could not print a test page. Only the USB printer came up, not connected.

Connected USB - tried to print - messages "printing", then "printer unreachable"

In Chromebook settings, only USB is listed.

SO...

I now have some workarounds to print, but I have found no way to scan.

Mopria scan app - 2 printers listed

• HP Laser Jet MFP M28w (6AF5D6) Ready to scan - selected it - pressed SCAN - Scan in progress - Scan failed. Later listed the printer as unknown status - selected it - blank screen with unknown status - then printer no longer listed
• Direct-d6-HP M28 LaserJet - not connected but phone settings says "Connected/no internet" - selected it - Connecting (pop-up) Approve the connection on the scanner display, if required. Only option available is CANCEL. - gave up

HP Smart

Add a printer already connected to the network.

Displays HP Laser Jet MFP M28w (6AF5D6)

Selected it - appears connected - says load paper - loaded paper - shut down app and started - still says load paper - turned printer off and on - solid Wi-Fi light - started HP smart - load paper has disappeared

Printer reports delays and delays - gave up.

Printer information displays model name, serial number, service ID, firmware version, IP address 192.168.68.54

Try to add the printer manually in Chrome OS using the above address - failed.

Later I learned from a network summary that the address is for the embedded web server. I tried connecting to the embedded web server but it failed. 

Print documents worked.

Printer scan - new screen with "Printer initialization" delaying until "There is no connection to the printer Try again" displayed - gave up

No scanners available in Chrome OS scan app