Here's a sample GraphML file that demonstrates the problem. Nodes/relationships are loaded fine, but no attributes.
GraphML.txt

Of course, please rename "GraphML.txt" to "GraphML.graphml" for loading. I had to change the file extension so I could upload it.

Notes: we might assume String type for undeclared attributes, since Neo4j APOC does this, but I am not sure that's valid GraphML according to http://graphml.graphdrawing.org/specification/primer/graphml-primer.html

Original topic: http://forum-gephi.org/viewtopic.php?f=29&t=5939

The actual XML is getting beyond my expertise, but I posted over at the APOC site (portion of Neo4j that generates the GraphML); perhaps they will chime-in... neo4j-contrib/neo4j-apoc-procedures#258

Can you try if this was fixed as indicated in neo4j-contrib/neo4j-apoc-procedures#258 please?

Did it work?

I am still seeing this issue with APOC 3.1.3.7, despite neo4j issue 258 being marked as closed.

Is it producing the correct output?

I am not sure whether the output is correct according to the graphml standard, but Gephi 0.9.1. fails to recognise the node or edge attributes exported by APOC. A snippet of an exported graph is shown below. I don't know whether this is a bug in Gephi or a bug in APOC.

<?xml version="1.0" encoding="UTF-8"?>
<graphml xmlns="http://graphml.graphdrawing.org/xmlns" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://graphml.graphdrawing.org/xmlns http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd">
<graph id="G" edgedefault="directed">
<node id="n0" labels=":Asset"><data key="labels">:Asset</data><data key="asset_id">Ua8oJEML7KXcvUTzL2g9WvJs9xyXTrj8YvJkzZ</data></node>
<node id="n1" labels=":Transaction"><data key="labels">:Transaction</data><data key="txid">74ac74b7b1fca6557cac3ce4d79a11f63c65d40f51eded347c0c43b532728cef</data></node>
<node id="n2" labels=":BTCAddress"><data key="labels">:BTCAddress</data><data key="hash">1DwmXwjNfFgdzA9yvwGPcu6kfv3znGBN7n</data></node>
<node id="n3" labels=":BTCAddress"><data key="labels">:BTCAddress</data><data key="hash">3KBSjKsSc4VKCfoWnj1fe8XHRhiG52gYZA</data></node>
<node id="n4" labels=":Transaction"><data key="labels">:Transaction</data><data key="txid">6489c12b5c90963cae7edaa0e91554fd29f2737d83d0af7e21732ad081d6481a</data></node>

It seems it's still not generating the key headers, that should look like:

<key id="labels" for="node" attr.name="labels" attr.type="string"/>

has there been any progress at all on this issue? Same problem

@snow-frog the issue is still open in neo4j neo4j-contrib/neo4j-apoc-procedures#466