Django templates issue in version 1.4.3

I am trying to migrate a very old Django/Python app(version 2.6) to new OS version. Due to dependency limitations I cannot migrate the app to Python3. While migrating template issue came in /lib/python2.7/site-packages/django/forms/ in new, line 215.

Error that came is as follows:
Unknown field(s) (a, l, _) specified for Template

Request Method: GET

|Django Version:|1.4.3|
|Exception Type:|FieldError|
|Exception Value:|Unknown field(s) (a, l, _) specified for Template|
|Exception Location:|/opt/virtualenv/lib/python2.7/site-packages/django/forms/ in new, line 215|
|Python Executable:|/usr/bin/python|
|Python Version:|2.7.5|

Any ideas how can I resolve this.

Are you saying that this system works with Django 1.4.3 and Python 2.6, but fails with Python 2.7?

If so, I’d first try running this on Django 1.4.22 / Python 2.6. Then, if that works, I’d try upgrading Python to 2.7 to see if that works.

If those upgrades don’t give you the desired results, then you need to decide what your final objective is.

Yes on a very old server the same Django app is working fine with Django 1.4.3 and python 2.6.
I have to migrate that app to RHEL 7 system which has python 2.7.5 installed by default.
I will try to run it on Python 2.6 and see if it works.
Thanks for the suggestion.