MySQL Database

If "java -version" fails to do the right thing then you can't expect FSAL to work correctly. For the DOS shell case, you must set PATH to include the ...\jdk\bin directory.
To deal with the Builder problem, first start by verifying that you can run anything from the Builder assuming that isn't what you already did. Start by unchecking the boxes you shared above. Then on the General tab, set a valid value that points to Internet Explorer (exe) in the Web Browser field.
Try to run your form. Does it work?
By the way, you should uninstall the JRE that is installed with the JDK and install the 32bit JRE if you plan to use IE or Edge.

The query string in your command line URL has "@" separating the parameters but it should be an ampersand "&"
Ben

@ben-g2 : You're right! I didn't pay attention to that . Fixing that, I've been able to run the form (with the standalone runtime option) via the command prompt :
Still, I really need to run it by clicking on the "Run application Forms" button.
@michael-ferrante-oracle : I've unchecked the two options as you asked me to do :
and I've set Internet Explorer as Web Browser :
However, when running the form, the browser page opens and gets stuck as shown in the screenshot below :
By the way, I'm actually trying to run it with the stanalone runtime option not via web browser. As an attempt to fix that, I've added the directory path below to the "Path" environment variable :
C:\Oracle\Middleware\Oracle_Home\oracle_common\jdk\bin
Afterwards, I restarted my computer.
But, nothing happens when clicking on the run button. So, it seems that it wasn't the correct path. Right?
I've actually spotted two different paths when looking up for the "jdk" folder :
However, the path that I mentioned above seemed to me the probable one. You see what I mean?

@ben-g2 Good catch. Not sure how I missed that.
@moslem Let's verify that Java is being correctly found by the Builder. Can you open the Builder Help? If not then the Builder is not correctly finding Java and this would explain why FSAL isn't working.

Yes, I can open the Builder Help. But, which submenu would you like to check out?
Here are some screenshots that show each one of the Help submenus :
(Help content)

(Documentation library)

(User Forums)

(Oracle Technology Network)

(About Form Builder)

As you can notice, it tells me that the page can't be shown for the submenus below :
Documentation library
User Forums
Oracle Technology Network

The fact that the Builder Help Navigator opens suggests that the Builder is correctly finding Java. However, the fact that you are unable to open any of the web pages suggests your machine is either not connected to the internet or does not have access to the internet or there are needed proxy settings missing from your machine.
This may be a clue as to why the Builder cannot launch FSAL. I would recommend removing the "localhost" reference in Application Server URL and using the actual hostname or IP address. The easiest way to get there is to simply press the Reset to Default button.

I see...
I've pressed the Reset to Default button, and I've also checked the Standalone runtime option :
Still, nothing happens when clicking the "Run application Forms" button! It is a Java issue, isn't it?
Actually, there is something that I really doubt about. It is whenever I run the following command-line: java -version ,
it tells me that the Java SE Runtime Environment can't be found.
That might be another clue. Right?

The java -version failure might be related to the problem but unlikely if the Help opens, which you said it did.
In the System PATH remove ALL references to Java. There may be more than one. Then only add back this one:
C:\Oracle\Middleware\Oracle_Home\oracle_common\jdk\bin
Also be sure you have not improperly altered the Forms runtime environment configuration (e.g. default.env). Similarly, ensure that it references the correct jdk\bin
Exit the Builder if it is open then retest.

've changed the "PATH" environment variable value from this one:
C:\Program Files (x86)\Common Files\Oracle\Java\javapath;C:\Users\Abbassi\Downloads\WINDOWS.X64_193000_db_home\bin;C:\ProgramData\Oracle\Java\javapath;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\DTS\Binn\;C:\HashiCorp\Vagrant\bin;C:\Oracle\Middleware\Oracle_Home\oracle_common\jdk\bin
to this one:
C:\Users\Abbassi\Downloads\WINDOWS.X64_193000_db_home\bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\DTS\Binn\;C:\HashiCorp\Vagrant\bin;C:\Oracle\Middleware\Oracle_Home\oracle_common\jdk\bin
So, as you can see, I've removed all the references to Java except that very path that I had already added.
Concerning the Forms runtime environment configuration, I haven't made any changes in it. However, when looking up the default.env file, I found four ones :
Here is the PATH variable value in each one of them :
PATH=C:\Oracle\Middleware\Oracle_Home\bin;C:\Program Files\Java\jdk1.8.0_221\jre\bin\client;C:\Program Files\Java\jdk1.8.0_221\bin
PATH=C:\Oracle\Middleware\Oracle_Home\bin;C:\Program Files\Java\jdk1.8.0_221\jre\bin\client;C:\Program Files\Java\jdk1.8.0_221\bin
PATH=%ORACLE_HOME%\bin;%JAVA_HOME%\jre\bin\client;%JAVA_HOME%\bin
PATH=%ORACLE_HOME%\bin;%JAVA_HOME%\jre\bin\client;%JAVA_HOME%\bin
After exiting Builder, I reopened it and retested. But, it keeps giving me the same result, and nothing has changed. Nothing happens.
Is there anything wrong in my Forms runtime environment configuration?

Yes, there is probably something wrong, but I am not convinced its Forms. The fact that your shell (DOS) is not correctly displaying the installed Java version apparently due to a messed up Registry entry is concerning. This is why I recommended you uninstall all the Java versions and only reinstall the JDK 8 (64bit) that was used to perform the product installation. The reinstall process may correct the Registry issue. Note that I do not recommend installing the JRE that is packaged with the JDK.
However, if you are new to the FMW product(s) and relatively new to Java installations on Windows, I don't recommend blindly uninstalling then reinstalling because you could end up breaking your Forms environment worse.
Likely the root issue can be identified and fixed, but sometimes it's just faster to uninstall, cleanup, and start over. For as much time as you've spent chasing this already, I could have reinstalled dozens of times.

I got your point. Well, I guess it would be better if I try a different approach which is using Web Browser instead of FSAL when running forms.
In this context, I would like to ask you one more question if you don't mind : When running a form for the first time, it asks me to connect to database :
However, it keeps asking me the same thing whenever the form is run and open on browser as you can see in the screenshot below :
Is there any possibility to avoid such connection? As you know, it's kind of annoying to do it over and over knowing that running forms may be done dozens of times even hundreds of times a day.

If you have successfully connected to the DB in the Builder before running the module, typically you will not be prompted again for the DB credentials unless the runtime fails to connect. However, in your case where you are using such an odd user name (inclusion of special characters) there may be issues because I do not believe the Builder will pass the needed quotes with the call.
Also, as mentioned before, you must connect to the PDB.
I will say that long term, using a username with special characters will be problematic as you move from tool to tool.

I see..
I've actually created a common user called c##aimen using the two command-lines below:

CREATE USER c##aimen IDENTIFIED BY my_password CONTAINER=ALL;
GRANT dba TO c##aimen CONTAINER=ALL;

So, as you know, the user name has to start with c## in this case.
Morever, I've checked out that I'm connected to the PDB since I've run the command line below:

ALTER SESSION SET CONTAINER = ORCLPDB;

You see what I mean?

Sorry, I'm as much of a DBA as I am a brain surgeon, which I am not. Why do you believe that the PDB user must start with "c##"? I/we use standard naming conventions. For example I have a "SCOTT" user in my test DB (PDB).

Alright! I got it
Bunch of thanks for your tips

Why do you believe that the PDB user must start with "c##"?
Moslem created this user as common user in the CDB$ROOT, therefore he had to follow the requirement to give it the c## prefix.

Oooops! Excuse me, Sir! But, it seems that doesn't work for me too
I've created a user having the name as Scott and the password as tiger. But, it keeps showing me that stuff whenever running the form.
Anyways, I'll create a new discussion talking about that in details.