Cannot save custom template due to CSRF protection key

[rubiksw]

I use a heavily modified copy of the Nexxe template. I am at a point where I cannot save any changes to my template files due to the following error:

 The CSRF protection key did not match. This may indicate a plugin or theme is out of date. Please contact technical support for more information.

I have made changes to the Nexxe theme to better suit my community and layout, so updating my "copy" is not an option. Even then I am no longer given the option to download a version which I could upload since the changes to themes introduced in 4.6 (or maybe 4.5). 

I am in a position where I can no longer make any changes to my site's layout. If someone has any solution to this, please let me know. I have paid my annual dues and kept an active subscription to the Nexxe theme, so the fact that I am unable to modify MY template due to this CSRF key because I made a copy and modified the template is outrageous. 

 

Note: Trying to save any changes to the theme's HTML returns the following error message: This theme file could not be saved

In the browser's console, I see a 403 error with the CSRF protection key error listed above in RED. 

Edited June 18, 2022 by sbs_rubik

[rubiksw]

I'm not 100% certain, but setting the parent theme to the up-to-date version of Nexxe theme may allow me to make changes to my template. Will report back if I continue to have issues. 

[Jim M]

There could be 2 things going on here:

1. mod_security or another security module may be blocking you here on your server if you are tripping a rule. Your hosting provider or server administrator would need to disable this and review your error log entries to assist you so this won't happen.
2. There may be a third party application/plugin causing an error with the CSRF key required to submit the page here. You will want to try to disable those and save your theme.