The issues seem to be resolved and I haven't gotten any further error messages after following the instructions above. I'll report back again in a few hours.
I do want to say that the add-on worked fine and as it was supposed to, even though it provided server errors in the admin control panel.
I have changed the style properties setting per below, and re-enabled the ElasticSearch Essentials add-on. Will let you know what I observe.
By the way, the test message that I sent just a few minutes ago is working fine and the other account I sent it to received it.
I just how got another error:
TypeError: Argument 1 passed to EAEAddons\QuickMessage\XF\Entity\User::canQuickMessageWith() must be an instance of XF\Entity\User, null given
Generated by: Unknown...
Let me see if the errors go away. I should see errors (or none) in the next hour or two, as they seem to come pretty regularly in the error logs.
If no errors, I'll do as you say above and wait for the update. If I get errors, I'll post them to you.
OK, I will disable the ElasticSearch Essentials and see if I get any more errors. The add-on has been working fine despite the errors, from what I can tell.
UPDATE -- I have disabled ElasticSearch Essentials. I'll report back in the next couple of hours to see if further errors have been...
I am getting many dozens of server errors after upgrading to the new version of the add-on:
TypeError: Argument 1 passed to EAEAddons\QuickMessage\XF\Entity\User::canQuickMessageWith() must be an instance of XF\Entity\User, null given src/addons/EAEAddons/QuickMessage/XF/Entity/User.php:34...