Internal Concurrent Manager status could not be determined.

To resolve this, do the following steps.

1. Make sure that there are no concurrent processes still running. ps -ef | grep FNDLIBR
2. Use sqlplus, login as APPLSYS
3. delete  from fnd_concurrent_processes;
   Don't panic if it deletes a lot of rows this table holds a lot of useless history information and should be cleaned up every so often.
4. update fnd_concurrent_queues set running_processes=0;

Now restart your concurrent managers, which should start up without any errors in the log file at all.
Then see if the requests go through OK.