I have tried to fix it myself, but it looks like quite a large amount of work.
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(567,33): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithChildren.childNodes does not override any function, did you mean to override 'std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.Node.childNodes'?
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(573,28): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithChildren.firstChild does not override any function, did you mean to override 'std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.Node.firstChild'?
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(577,28): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithChildren.lastChild does not override any function, did you mean to override 'std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.Node.lastChild'?
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(582,18): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithChildren.insertBefore does not override any function, did you mean to override 'std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.Node.insertBefore'?
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(620,18): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithChildren.replaceChild does not override any function, did you mean to override 'std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.Node.replaceChild'?
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(625,18): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithChildren.removeChild does not override any function, did you mean to override 'std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.Node.removeChild'?
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(649,18): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithChildren.appendChild does not override any function, did you mean to override 'std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.Node.appendChild'?
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(680,18): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithChildren.hasChildNodes does not override any function, did you mean to override 'std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.Node.hasChildNodes'?
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(684,18): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithChildren.isAncestor does not override any function, did you mean to override 'std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.Node.isAncestor'?
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(696,33): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithChildren.textContent does not override any function, did you mean to override 'std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.Node.textContent'?
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(711,28): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithChildren.textContent does not override any function, did you mean to override 'std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.Node.textContent'?
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(1310,33): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithNamespace.nodeName does not override any function
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(1312,33): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithNamespace.localName does not override any function
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(1318,33): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithNamespace.prefix does not override any function
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(1322,28): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithNamespace.prefix does not override any function
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(1338,33): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.NodeWithNamespace.namespaceURI does not override any function
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(2274,28): Error: function std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)).DOMImplementation.EntityReference.readonly does not override any function
..\..\Users\rikki\AppData\Roaming\dub\packages\std-experimental-xml-master\std-experimental-xml\source\std\experimental\xml\domimpl.d(2419,42): Error: template instance std.experimental.xml.domimpl.DOMImplementation!(string, shared(GCAllocator), bool delegate(DOMError!string)) error instantiating
source\app.d(12,3): instantiated from here: domBuilder!(Cursor!(Parser!(SliceLexer!(string, void function(), shared(GCAllocator), cast(Flag)true), void function() pure nothrow @nogc @safe, cast(Flag)false), cast(Flag)true, void function(CursorError) pure nothrow @nogc @safe))
I have tried to fix it myself, but it looks like quite a large amount of work.