Jheroen

In their account settings, in Security and Privacy

There is no harm in leaving them present, no. Many do

And /api/.htaccess, if it exists.

There is no built in way to do this, however what you could do is this, after making sure you are on the latest release and things are working properly:
Make a full backup in case of issues, and turn your site offline while you do this Delete all files and folders apart from
/applications/
/api/.htaccess (if you have one)
/datastore/
/plugins/
/uploads/
constants.php (if you have one)
conf_global.php
.htaccess Upload a fresh set of files from your client area  
Note, this is something done at your own risk, and does not account for any changes you may have made from default, such as upload location changes, third party items etc
 

Not other than the default htaccess for rewrites, which you can find in System>Search Engine Optimisation and download from there

No.
but go to the expected URL in the browser (www.domain.com/robots.txt) and you will see the content.

I have reescalated your ticket 

You will receive communication via email.

Thank you. Please be advised I have moved this to a ticket so we can further investigate.

Please could you update to the latest release? If you are then still seeing the same issue, please ensure you have tested with no 3rd party items enabled, and on a default theme. Once you have done this, if you are still seeing the same, please update all access details on file

We are unable to advise on specific types, only on the locations that can be used which are shown here
With automatic ads, they will place based on how they think they will look best on that specific site. Therefore it is indeed plausible that it will break one theme and not another
 

Yes, automatic ads and yes in the default theme it's working OK, added a ticket with ipsthemes

Stu_m asked for more detail - I provided it.

You would need to disable all 3rd party items and test this again, enabling them until you find the cause. The issue you are having there is resulting from a 3rd party product. In this case it's the "members country" item, but there may be more

You can create a saved action to lock the topic and use this:
 

There is no functionality that would allow a user themselves to close only their own topics. This is a moderator function, and would require them to be a moderator to achieve. That would mean they can close other peoples topics

No problem. If you are happy with the resolution there, all good.

Hi @Marc Stridgen i managed to fix this by googling around, the fix was rather easy, rename the current table to core_achievements_log_milestones_1 and the install went on without a glitch.
 

Add a file constants.php starting with "<?php" (if it doesn't already exist) and then add this new line to it:
 
define( 'RECOVERY_MODE', true ); Get into the ACP, disable whatever you need to disable, and then remove the line from the constants.php afterwards.

We disable all customizations going from 4.4 -> 4.5 because they are generally not immediately compatible.
We do not automatically disable customizations normally during upgrades (i.e. they won't be disabled during point releases in 4.5).

I believe this is something you need to configure in your Google CSE settings. 
Edit Search Engine -> Search Features -> Advanced tab -> Websearch Settings -> Set Link Target to: _self

New version released.
Thanks to @Jheroen for helping me with the debugging and testing.