Blank page after file upload

Question

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.

Answer 1

Hello,
thank you all for help. It turns out that it was indeed issue with the code itself. It's strange that it doesn't manifest without Apex Listener, but it was incorrect code.
I'm a system administrator (not a programmer) and I assumed that since the only change to the system was added Listener, it must be a problem with incorrect configuration - I was wrong :-)
When I tried replicating the problem on apex.oracle.com, I noticed that After Processing branch redirecting to another page was completely missing from our code. When I removed the branch from apex.oracle.com, it stopped working (logically) too - the solution was therefore to add After Processing branch redirecting to some other page with "include process success message" checked.
I still don't understand how it could have worked without Apex Listener in the first place :-)