Error in Comments creation

[amanaltudo]

We have implemented weblog v4.2,Website is upgraded from sitecore 7.x to 10.2.
Comments are not getting through in our blog post.

Comments are not created under the blog item in master DB
Below file contains sitecore log for the error
Weblog comment error.txt

[adeneys]

Hi @amanaltudo

WeBlog 4.2 has not been tested with Sitecore 10.2, which was released after WeBlog 4.2 was.

Checking over the log messages you provided, an error occurs inside the Sitecore.Modules.WeBlog.Pipelines.CreateComment.CreateCommentItem.Process() method when the Sitecore.Data.DefaultDatabase.SelectSingleItem() method is invoked. The code likely making that call can be found at https://github.com/WeTeam/WeBlog/blob/master/src/Sitecore.Modules.WeBlog/Pipelines/CreateComment/CreateCommentItem.cs#L76.

The first thing that pops out at me is the fact the CreateCommentItem class is using fast query to check if an item with same name as the comment item already exists. Fast query was deprecated in Sitecore 10.1, so I'm wondering if that's causing the issue.

You could try subclassing the CreateCommentItem class and overridding the BuildFastQuery method to use a normal query instead of a fast query, and see if that solves the issue.