Cindy - I think I found an issue with the Bootstrap and the Remember Me plugin.
The plugin puts a "Remember Me" checkbox on the login page. However, due to the input class of the checkbox, the actual checkbox isn't displaying.
The code looks like this:
<input class="custom-control-input" type="checkbox" name="permLogin" value="1" checked="checked" id="permLogin">
As you can see in the screenshot, it doesn't display the actual checkbox:

Now, if I manually change the class to anything else, it works. The problem is that I don't know where to change it.
I ASSUME that I need to change it in the observers/class.remember_me_observer.php on this line:
zen_draw_checkbox_field('permLogin', '1', $this->checkbox_default, 'id="permLogin"') .
'<label class="checkboxLabel" for="permLogin" title="' . TEXT_REMEMBER_ME_ALT . '">' . TEXT_REMEMBER_ME . '</label>';
However, I don't know how! I did try to edit that line of code above to say 'id="permLogin" class="testing", but all that did was create a checkbox with the class saying class="custom-control-input testing".
The problem is that the checkbox itself won't display with the "custom-control-input" class. Perhaps there's a CSS edit to be made?
Any help is appreciated.