Hi,

1. Do we talk about Joomla 3.10 or Joomla 4 ?
2. Do you have J2Store component installed? If yes, read tip #3 from: https://www.joomshaper.com/documentation/helix-framework/helix-ultimate-2/troubleshooting-faq
3. What text editor you set as deafult? It should be TinyMCE or JCE.
4. Does your template override K2 views?

1. Joomla! 3.10.2
2. component J2Store not installed
3. TinyMCE
4. I did not see such settings in the template

I want to note that everything works fine in Joomla materials

I found the reason after which SP Page Builder stops working in K2: this happens after installing the language pack (rus) for K2

delete/disable admin RU language and check again.

Naturally I checked!

I found that even if you remove these lines even from the English language pack (en-GB.com_k2.ini):

K2_THE_ENTRY_IS_ALREADY_IN_THE_LIST = "The entry \" ENTRY_NAME_HERE \ "is already in the list!" K2_THE_ENTRY_WAS_ADDED_IN_THE_LIST = "The entry \" ENTRY_NAME_HERE \ "was added in the list."

SP Page Builder stops working !!!

Pay attention to this!

Thanks, I already added into SPPB documenantion - Troubleshooting .

K2 UPDATE

According to last posts from offcial K2 forum, on your place I would consider migration from K2 into Articles as soon as possible. No k2 new versions, and no k2 support for Joomla 4.x , no support for PHP 8. In general, all users gets the impression that the project is collapsing, only the delvelopers do not want to announce it. Do not use K2 component in your projects. Otherwise you will stuck with no PHP and Joomla Update possibility. Honest advice.

We also stop K2 support in SPPB 4