[AT&T Samsung Galaxy S 4 Android Development] CPA Poke:
Here's what you do.

Download the free app "Zarchiver" from the Play Store.

Download your favorite text editor. I recommend the Android port of Notepad++, found here: https://play.google.com/store/apps/details?id=gloom.notepad

Download Task's ROM.

Open the APP and navigate to where you downloaded the ROM. Click the ROM, and choose "View".

Follow this folder path:

META-INF >> com >>> google >>> android

Click on the "updater-script" file, choose "Extract", then hit the back button on your phone until you get out of the ROM zip. When you get to the directory you want to save the file in, then click the button on the top of the screen that is a little arrow pointing to a dot.

Use Zarchiver or any other file manager to navigate to where you saved the file and open it, using the text editor you downloaded.

The top lines of the script should look like this:

assert(getprop("ro.product.device") == "jflteatt" || getprop("ro.build.product") == "jflteatt");
package_extract_dir("install", "/tmp/install");
set_perm_recursive(0, 0, 0755, 0644, "/tmp/install");
set_perm_recursive(0, 0, 0755, 0755, "/tmp/install/bin");
show_progress(0.500000, 0);
ui_print("******************************************");
ui_print("* Welcome to Task650's... *");
ui_print("* ______ _____ __ __ _____ *");
ui_print("* /\ _ \/\ __`\/\ \/\ \ /\ _ `\ *");
ui_print("* \ \ \L\ \ \ \/\ \ \ \/'/'\ \ \L\ \ *");
ui_print("* \ \ __ \ \ \ \ \ \ , < \ \ ,__/ *");
ui_print("* \ \ \/\ \ \ \_\ \ \ \\\`\ \ \ \/ *");
ui_print("* \ \_\ \_\ \_____\ \_\ \_\\\ \_\ *");
ui_print("* \/_/\/_/\/_____/\/_/\/_/ \/_/ *");
ui_print("* *");
ui_print("******************************************");
ui_print("******************************************");
ui_print("******************************************");
ui_print("* Compiled: Mon Oct 7 05:47:54 PDT 2013");
ui_print("* Device: SGH-I337 (jflteatt)");

The culprit that is causing your Status 7 error is the very first line, beginning with "assert(getprop(....".

Delete that line completely.

The script should now look like this:

package_extract_dir("install", "/tmp/install");
set_perm_recursive(0, 0, 0755, 0644, "/tmp/install");
set_perm_recursive(0, 0, 0755, 0755, "/tmp/install/bin");
show_progress(0.500000, 0);
ui_print("******************************************");
ui_print("* Welcome to Task650's... *");
ui_print("* ______ _____ __ __ _____ *");
ui_print("* /\ _ \/\ __`\/\ \/\ \ /\ _ `\ *");
ui_print("* \ \ \L\ \ \ \/\ \ \ \/'/'\ \ \L\ \ *");
ui_print("* \ \ __ \ \ \ \ \ \ , < \ \ ,__/ *");
ui_print("* \ \ \/\ \ \ \_\ \ \ \\\`\ \ \ \/ *");
ui_print("* \ \_\ \_\ \_____\ \_\ \_\\\ \_\ *");
ui_print("* \/_/\/_/\/_____/\/_/\/_/ \/_/ *");
ui_print("* *");
ui_print("******************************************");
ui_print("******************************************");
ui_print("******************************************");
ui_print("* Compiled: Mon Oct 7 05:47:54 PDT 2013");
ui_print("* Device: SGH-I337 (jflteatt)");

Do what you have to do to save the changes, then exit the file.

Open Zarchiver and navigate back to the directory you extracted the updater-script from earlier.

Hit the button on the top right of the screen (it looks like 4 or 5 horizontal lines, like writing on a paper), then click "Add", then "File". Navigate to where you saved the updater-script that you modified earlier, then click the file so it is highlighted. Click "Add" on the bottom right of the popup dialog.

Let the app do its work.

Flash away :)

WARNING FOR ANYONE ELSE FOLLOWING THESE INSTRUCTIONS:

These asserts are included in these ROMs' updater-scripts for a reason - to protect flash-first-learn-later users. ONLY PERFORM THESE EDITS IF YOU ARE 100% POSITIVE THAT THE ROM IS COMPATIBLE WITH YOUR DEVICE!

Also, if you're needing to make this edit, you're almost always going to have to flash a custom kernel for your variant.

So you've been warned. However, as long as your device is compatible and you follow my instructions precisely, you should have no problem at all flashing the ROM in question.

PS: If you're now looking for a bunch more ROM flashing options, check out the i9505 international S4 original android development forums. :) If you do end up doing so, the only difference from my instructions above will be that there will probably be multiple "assert(getprop" lines at the beginning of the script. Make sure you delete them all.