Invalid Argument

Hi, if you deleted the plugin, it’s 100% impossible that you’d be getting that error because that line of code wouldn’t run (given you would have deleted the file in the error which located in our plugin).

What you can probably do to fix that error though is activate Meta Tag Manager go to Settings > Meta Tag Manager and click ‘save settings’. If you’re not seeing the MTM settings on there, that’s not something I’ve ever come across but I’d bet it’s likely another plugin blocking MTM from running in some way or another.

Well it’s nice that it is 100% impossible but it is happening. Lets look at some screenshots:

#1 The plugins currently installed on the website, note that MTM is not listed
https://drive.google.com/file/d/0B0EXa5BeseM_a0N1Y2R1RTlucXc/view?usp=sharing

#2 Logged into my FTP to verify, yup in the plugins folder there is not MTM folder
https://drive.google.com/file/d/0B0EXa5BeseM_TlpILWlEbGFBRG8/view?usp=sharing

#3 After checking that MTM is not installed, I tried to activate Akismet at see the following screen
https://drive.google.com/file/d/0B0EXa5BeseM_R2VJNkdfZndtZkE/view?usp=sharing

I don’t know what else to do, this plugin is definitely trying my hands

What about the ‘must use’ plugins you have on your first screenshot. Have you tried clicking on that link and seeing if our plugin is showing up?

I’d suggest renaming the wp-content/mu-plugins folder to something else e.g. xmu-plugins temporarily and see if that helps.

It’s very odd though… your PHP error is saying that it’s located in wp-content/plugins, but then your plugins folder is showing only those two plugins. Nothing adds up.

We just released version 2.1 fixes that warning from showing up.

However, given your site shows our plugin as not active or even existent for that matter, I’m not sure how you’d update.