Q: iMessage doesn't working and says no conversation

Did you restart after deleting the .plist?

Do a backup, preferably 2 backups on 2 separate drives.

Quit the application.

Go to Finder and select your user/home folder. With that Finder window as the front window, either select Finder/View/Show View options or go command - J.  When the View options opens, check ’Show Library Folder’. That should make your user library folder visible in your user/home folder.  Select Library. Then go to Preferences/com.apple.iChat.plist.  Move the .plist to your desktop.

Restart the computer, open the application and test. If it works okay, delete the plist from the desktop.

If the application is the same, return the .plist to where you got it from, overwriting the newer one.

If that doesn’t work, repeat the above but delete the com.apple.imagent.plist

Thanks to leonie and Ralph Johns (UK) for some information contained in this.

Hi,

So the app opens and show you the main window but this does not look like you expect.

It appears to have no list in the Side bar on the left so the right hand Pane says no conversation selected.

It would really help to know which .plist you deleted not that any of them seem to hold the list on currently displayed chats.

This seems to come from the chat.db items which - possibly - you have lost the ability to Read.

If you open the Hard Drive icon and then Users you will see a folder with your Shortname on it and a Little House icon instead of the normal Folder one.

Everything in this Folder you should "Own" and have Permissions to Read and Write to.

In the case of a picture file this mean you can open it and the Save it after changes.

There are other Files that you Own (or should do) that the OS and the apps Write to and do so in your name as it were.

Open a Finder window.

Use the GO Menu whilst holding down the ALT Key and select the Library that appears in the list.

Now navigate to Messages.

This should hold three chat.db items (the ending and names vary) and the Attachments folder.

Highlight the chat.db item

If you right-click you can select Get Info.

In the Panel that appears scroll to the bottom and highlight your shortname and then unlock the Padlock

Use the Cogwheel type icon under the list.

It should have Greyed out text saying "make yourshortname (me) the Owner"  (Greyed out means you Own this as the action is already done)

Repeat for the other two files.

Example Pic. The Info Panel alongside the  Messages folder

There are many more files involved that could have also lost permissions but this will give as an idea.

9:23 pm      Sunday; March 13, 2016

Understood.

9:39 pm      Tuesday; March 22, 2016

You are welcome.