FileSystemWatcher created event
Several odd elements in this code.

Pointless variables

These variables look pointless:

        var fullPath = e.FullPath;
        var changeType = e.ChangeType;


You could use e.FullPath and e.ChangeType where you need it, the extra local variables don't seem to have any purpose.

Garbage not filtered out soon enough

It's very strange to execute this code every time a file is created:

        _extensionList.RemoveAll(r =&gt; string.IsNullOrEmpty(r.Trim()));
        _ignoreList.RemoveAll(r =&gt; string.IsNullOrEmpty(r.Trim()));


Why do you need to filter out the garbage every time instead of doing it just once?

Even better: how did garbage every enter these lists? It would be better to prevent that, and organize your code in a way that it's impossible to enter garbage into these lists.

Lastly, the result of r.Trim() will never be null, so the null-check is pointless.

Why not use a Set ?

Instead of putting the extensions and ignored extensions into lists, it would be better to use sets instead. It will it a lot more efficient to check if they contain an element or not, without the need for lambdas.

Exception handling

The try block is to large. It's better to limit the scope of try blocks, to make it easier to see the piece of code where an operation might fail.

Instead of catching a generic Exception, it's better to catch the most specific kind of exception that can be thrown.