ORDS, SODA & JSON in the Database

Hello,
we are facing problem with Apex Listener 2.0 connecting to Apex 4.1.1. The Apex Listener is deployed on Tomcat. Almost everything works correctly, with one exception - uploading files. After uploading file, blank page with url http://server:8062/apex/wwv_flow.accept is displayed and stuck there. The file, however, uploads successfuly. The same functionality (using the same page) works correctly when used without Apex Listener.
No error messages can be found, neither in Tomcat log nor in Apex Listener log.

I've experimented with several configurations uploaded from Listener admin in SQL Developer or minimal configurations from samples - this is my current config:

-----
Configuration properties for: apex
cache.caching=false
cache.directory=/tmp/apex/cache
cache.duration=days
cache.expiration=7
cache.maxEntries=500
cache.monitorInterval=60
cache.procedureNameList=
cache.type=lru
db.hostname=localhost
db.password=******
db.port=1521
db.sid=xe
debug.debugger=false
debug.printDebugToScreen=true
error.keepErrorMessages=true
error.maxEntries=50
jdbc.DriverType=thin
jdbc.InactivityTimeout=1800
jdbc.InitialLimit=3
jdbc.MaxConnectionReuseCount=1000
jdbc.MaxLimit=10
jdbc.MaxStatementsLimit=10
jdbc.MinLimit=1
jdbc.statementTimeout=900
log.logging=true
log.maxEntries=50
misc.compress=
misc.defaultPage=apex
security.disableDefaultExclusionList=false
security.maxEntries=2000
db.username=APEX_PUBLIC_USER
security.inclusionList=
sqldev.description=
sqldev.name=apex
-----

As I saw in other thread, blank pages are most commonly caused by mismatched static files - however my i/apex_version.txt matches the server version, so I don't suspect that to be the case.

Would you have any ideas on what to check or what could possibly be wrong?

Thank you.