Serialization issue: creating of lightweight edges

[max-kuk]

OrientDB Version: 3.0.10

Java Version: 1.8

OS: Linux Ubuntu 18.04

Expected behavior

By creating only normal edges via PHPOrient or creating of leightweight/normal edges in OrientDB Studio it runs without any error.

Actual behavior

OrientDB seems to be to have some problems with the serialization. In my case, i use PHPOrient and it can't serialize and execute queries by creating lightweight edges.
Error: Cannot serialize record: {class: E, out: #14:882, in: #16:2} (lightweight)

Firstly I thought it is a PHPOrient Issue and have already posted issue. But it seems to be a OrientDB problem.

Steps to reproduce

1. create 2 Vertices (Flight and Airport)
2. execute ALTER DATABASE custom useLightweightEdges=true
3. try to create lightweight edge by running this query: CREATE EDGE FROM (SELECT FROM Flight WHERE uuid = '9510343d-db9a-5e30-9155-e6de3f482160') TO (SELECT FROM Airport WHERE airport_code = 'FRA')