Linux Cinnamon Mint 17.3 - panel applet broken

Question

Ever since the update to 17.3, the update manager of cinnamon mint in the panel no longer shows a blue insert with the number of pending updates when an update is available, as 17.2 did.

I have manually checked for updates and found them, hence the request.

Occurs on two substantially different PCs; one was a complete install from scratch, another was an in place upgrade.

This suggestion did not work:

Click on the Update Manager icon on your panel, then on "Edit" followed by "Software sources" followed by "Maintenance". Then click on "Fix MergeList problems". Finally, update the cache.

Nor did this:

Have you adjusted the settings regarding the delay between refresh? You may want to reduce the time between refresh. It may be too long.

or this:

Do you have the software manager or synaptic open in the background? Right click the tray icon and select Information:

There is no Information. There is About (which tells me it was written by [e-mail], no release number, and that I may click on the applet to launch the Update Manager) and Remove this applet.

Any hints there? No hints, clues, or Norwegian Blues.

Another suggestion:

Open the general settings of Cinnamon and disable the support for indicators
Probably you have to log off and back in.
The right click menu should now give the said (and additional) option.

Did Preferences | System Settings | General | Miscellaneous options | Enable support for indicators || and turned that off. Then, I rebooted. Right click menu unchanged. Applet appearance unchanged. Left-click and double-left-click do nothing.

How may I fix this?

Answer 1

There are two different applets named Update Manager now. The applet with the icon of a brown cube is the useless one with an invalid address listed under About.

I reset the panel to the default design, which removed the useless applet, and brought back the functional Update Manager icon which shows the number of pending updates.