BaseX event handling

Trying to update BaseX-node to handle events.
It works the 1st time:

21:19:01.858 [127.0.0.1:38155] LOGIN admin OK
21:19:01.861 [127.0.0.1:38156] LOGIN test1 OK
21:19:02.003 [127.0.0.1:38155] CREATE EVENT messenger
21:19:02.005 [127.0.0.1:38155] OK 143.0 ms
21:19:02.027 [127.0.0.1:38156] OK 13.41 ms
21:19:02.247 [127.0.0.1:38156] QUERY(0) for $i in 1 to 1000000 where $i=3 return $i OK 219.51 ms
21:19:02.248 [127.0.0.1:38156] QUERY(0) OK 0.5 ms
21:19:02.252 [127.0.0.1:38155] QUERY(0) db:event('messenger', 'Hello World!') OK 230.45 ms
21:19:02.254 [127.0.0.1:38155] QUERY(0) OK 0.76 ms
21:19:02.584 [127.0.0.1:38155] EXEC(0) OK 329.22 ms
21:19:02.943 [127.0.0.1:38156] EXEC(0) OK 694.17 ms
21:19:02.945 [127.0.0.1:38156] OK 0.34 ms
21:19:03.004 [127.0.0.1:38155] DROP EVENT messenger
21:19:03.005 [127.0.0.1:38155] OK 2.18 ms
21:19:03.006 [127.0.0.1:38155] EXIT
21:19:03.011 [127.0.0.1:38155] OK 6.03 ms
21:19:03.012 [127.0.0.1:38155] LOGOUT admin OK
21:19:03.014 [127.0.0.1:38156] EXIT
21:19:03.019 [127.0.0.1:38156] OK 6.57 ms
21:19:03.020 [127.0.0.1:38156] LOGOUT test1 OK

Then it hangs..

21:19:16.106 [127.0.0.1:38158] LOGIN admin OK
21:19:16.112 [127.0.0.1:38158] CREATE EVENT messenger
21:19:16.115 [127.0.0.1:38158] OK 27.79 ms
21:19:16.151 [127.0.0.1:38159] LOGIN test1 OK
21:19:16.192 [127.0.0.1:38158] QUERY(0) db:event('messenger', 'Hello World!') OK 0.98 ms
21:19:16.200 [127.0.0.1:38158] QUERY(0) OK 7.4 ms
21:19:16.207 [127.0.0.1:38159] OK 0.65 ms
21:19:16.220 [127.0.0.1:38159] QUERY(0) for $i in 1 to 1000000 where $i=3 return $i OK 7.77 ms
21:19:16.231 [127.0.0.1:38159] QUERY(0) OK 4.3 ms
21:19:16.253 [127.0.0.1:38158] EXEC(0) Error: null
21:19:16.732 [127.0.0.1:38159] EXEC(0) OK 459.42 ms
21:19:20.036 [127.0.0.1:38158] LOGOUT admin OK
21:19:20.042 [127.0.0.1:38159] LOGOUT test1 OK

What is that error?