Today i tried to add the language code to url. Most part or the site seems they work except the blog. All the blog posts exists, their new urls works normally, but they are totally empty. TOTALLY..

Any solutions?

On the otherhand, if i dont set different url, when i use 2 languages, how does the google check my page? It see two different versions of the same url? Does it understand that they are translated versions or what?

There is bug on this with basically all plugins.
Is addressed in 8.1.2

so i should update the osclass? You know i am using almost all your plugins. Am i going to face any incompatibilities?

thats what i see on backend:
Checking for updates...

Current version: 8.1.1
Congratulations! Your Osclass installation is up to date!

 So there is not version 8.1.2 for osclass

please tell me what to do to make it full funcional with different url for languages

i get these errors if that helps:

[07-Mar-2023 01:17:58 Europe/Athens] PHP Warning:  Undefined array key "s_name" in /home/hru33ujxrs7c/public_html/oc-content/plugins/blog/functions.php on line 287
[07-Mar-2023 01:17:58 Europe/Athens] PHP Warning:  Undefined array key "s_name" in /home/hru33ujxrs7c/public_html/oc-content/plugins/blog/form/author.php on line 18
[07-Mar-2023 01:17:58 Europe/Athens] PHP Warning:  Undefined array key "s_name" in /home/hru33ujxrs7c/public_html/oc-content/plugins/blog/functions.php on line 287
[07-Mar-2023 01:18:39 Europe/Athens] PHP Warning:  Undefined array key "fk_i_user_id" in /home/hru33ujxrs7c/public_html/oc-content/plugins/blog/form/article.php on line 4
[07-Mar-2023 01:18:39 Europe/Athens] PHP Warning:  Undefined array key "pk_i_id" in /home/hru33ujxrs7c/public_html/oc-content/plugins/blog/form/article.php on line 8
[07-Mar-2023 01:18:39 Europe/Athens] PHP Warning:  Undefined array key "pk_i_id" in /home/hru33ujxrs7c/public_html/oc-content/plugins/blog/functions.php on line 29
[07-Mar-2023 01:18:39 Europe/Athens] PHP Warning:  Undefined array key "i_category" in /home/hru33ujxrs7c/public_html/oc-content/plugins/blog/form/article.php on line 28
[07-Mar-2023 01:18:39 Europe/Athens] PHP Warning:  Undefined array key "dt_pub_date" in /home/hru33ujxrs7c/public_html/oc-content/plugins/blog/form/article.php on line 35
[07-Mar-2023 01:18:39 Europe/Athens] PHP Warning:  Undefined array key "i_view" in /home/hru33ujxrs7c/public_html/oc-content/plugins/blog/form/article.php on line 36
[07-Mar-2023 01:18:39 Europe/Athens] PHP Warning:  Undefined array key "s_image" in /home/hru33ujxrs7c/public_html/oc-content/plugins/blog/form/article.php on line 41

There is bug on this with basically all plugins.
Is addressed in 8.1.2

Means there is bug on Osclass with language codes in URL.
Do not use until fixed in 8.1.2