Let me start with the urgent comment: Do NOT copy configuration from old versions and drop them into the new environment. That is a bad idea for numerous reasons. The most obvious is because the new version has new parameters and changes, some of which are required.
Hopefully, in your version 10 environment you did not alter the [default] section of formsweb.cfg. If this is the case, then you can easily copy your customized sections into the new version's file. However, before doing anything like that, be sure that you stop the v11 Admin Server and Managed Server (WLS_FORMS). Do not try to do this with them running or your changes likely will get lost of ignored. The default.env should be similar. You can replace one-for-one entries, but do not replace any new entries found in the file. So, for example, you could copy your old FORMS_PATH and drop it into the new file. Comment out the existing one and use your in its place. And so on.
Ok, we can all calm down now.
The next thing to address is the this statement, "...compiled forms files on server A...". You also cannot copy compiled/generated Forms modules from one version to another. You must generate new "X" files (fmx, mmx, plx) in the new environment, using the new compiler.
As for using the Upgrade Assistant, there are some limitations for using it, such as needing to be on the same machine. However, regardless, my recommendation is that you not use it anyway. In most cases, you will have better success and an easier to maintain environment if you do things manually. UA is mostly helpful when you have significant and complex customizations throughout the stack (OHS, Web Cache, Forms, Reports, etc). For typical config changes, manually creating the new ones is going to be the way to go. It will also give you a chance to clean house by removing changes previously made that are no longer needed.
Thank you so much your kindly reply. I am very impressed about that your detail explanation.
It is my first time for migration and English is not my mother tongue so it is little bit hard for me .
Yes, I could not use old "X" files in the new environment. If you did, you can see error message on running time.
But I run new compiler's compiled fmx on new server, I see an error message FRM-1221: Cannot read file /middleware/asinst_1/FORMSComponent. I looked that folder and I granted chmod 777 but it still does not works. I will figure it out.
I will one-for-one entries from old one to new one. I am just worried about somewhat side effect after I migrated to new server because there is no document for migration to different machine on the Oracle Homepage.
Thank you again,
Without some investigation, I'm not exactly sure why you would be having problems with the compiler. However, be aware that you must be the installation owner in order to use the tools. Simply changing file permissions may not be sufficient. Also, be sure to use the compiler script found in the Instance Home and not the binary found in the Oracle Home. In other words, use /middleware/asinst_1/bin/frmcmp.sh This will ensure that the environment gets properly setup before the process starts.