Forbidden 403 Error Fabrik Administration

[ontarget]

Hi I upgraded a J310.11 site with to J4 /F4Beta. When navigating the backend (Fabrik lists, elements etc) the site will give a Forbidden 403 Error

"Forbidden
You don't have permission to access this resource.
Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request."

Also when making changes to e.g calc elements then I get a popup with

Please wait - still loading

I have ensured that I have a J4 htaccess file and i have the following php.ini file

allow_url_fopen=1
display_errors = Off
max_execution_time = 60
max_input_time = 60
max_input_vars = 1000
memory_limit = 256M
post_max_size = 15M
session.gc_maxlifetime = 1440
session.save_path = "/var/cpanel/php/sessions/ea-php81"
upload_max_filesize = 15M
zlib.output_compression = Off

Any ideas how this can be fixed?

 

[troester]

How did you upgrade?
Any error messages during the upgrade?
Did you clear all Joomla and browser cache?

Try to install the Fabrik beta package again.

 

[ontarget]

Thanks for the reply,
Yes joomla cache and browser caches' cleared.
I followed the skurvish instructions on github to the letter:
https://github.com/joomlahenk/fabrik/wiki/Upgrading-from-fabrik3.10-to-fabrik4
If i go into an element and try to modify it > click save / save and close then the forbidden 403 error shows, then after approx 15 seconds if you refresh you can access the e.g element or list plugin or whatever but the changes are not saved.
I will try to install the beta package again to see if that helps.

 

[ontarget]

UPDATE:
I reinstalled F but still the same issue.
So i setup the site on a completely different server and it works perfectly. So the issue is with the Server. If you have any ideas what could cause the issue on the original server? Htaccess? Thanks