I recently tried to move to SQL Server 2014. I can read the database and update records, but not reply or create new topics. I am a little frustrated by this issue. I was forced to make this more. Any ideas how to resolve this issue?

Perhaps it has to do with the identity seed. When you insert new data into a table, the identity seed increases.
Perhaps you can run a test on your server by creating a dummy table and use generic code to INSERT a new record into that dummy table. If you can do that, then try it on a copy of your FORUM_TOPICS table. If you can do that, then that might help you isolate the problem.

How did you move the database? As etymon said could be the table identity columns aren't set. shouldn't be a problem for Snitz, I have used every version of SQL without an issue.