Headstart Designer generated form crashes with Java EOF error

Question

When closing a form while in Enter Query mode, the form crashes & user is
disconnected from the database with error:
FRM-92100: Your connection to the server was interrupted.
Details:
Java Excepton
java.io.EOF Exception
at java.io.DataInputStream.readUnsignedByte(Unknown Source)
at oracle.forms.engine.Message.readDetails(Unknown Source)
at oracle.forms.netStreamMessageReader.run(Unknown Source)

Answer 1

Designer generates the ON-ERROR block level trigger. It has
execution style of BEFORE. Therefore, both the block level and
form level ON-ERROR triggers will fire.
Normally, in the block level trigger, Designer will generate
calls to its own message handling package to display any
constraint errors. However, Designer also allows you to specify
your own custom message handling package.
The package must contain:
- a procedure called PUSH
- a function called MSGGETTEXT, and
- a procedure called RAISE_FAILURE.
The preference MSGSFT, Package Used for Messaging, allows you to
record the name of the custom package.
Once you have recorded this in the preference, whenever you
generate a form, Designer will use your package and procedures
for its error handling code. That is why you see calls to
Headstart specific code in the block level ON-ERROR triggers.
If you want to customize the ON-ERROR triggers, you need to make
sure you understand how the MSGSFT preference is used. Read the
online help. Then, you can customize individual blocks by adding
application logic to the block, or you can add your own ON-ERROR
trigger to the object library in the CG$BLOCK object.
However, be warned that the Headstart error handling mechanism
depends on this code. Depending on what you do, you could end up
breaking things.