A severe error occurred on the current command. The results, if any, should be discarded.

I have a strange situation on a database, which are on SQL Server 2008 R2 Express SP2. The database size is something around 90 MB.
When a user try to insert a record inside one table, he receive an error message,  and the program is disconnected from the database. I tried to investigate this issue, and I discovered that when user try to insert one row  the trigger for insert invoke also the trigger for update and sql server crushes with "A severe error occurred on the current command.  The results, if any, should be discarded."
I have checked from SQL Server Management Studio to run a direct Update on the specific table. The same error occurred.
I have run DBCC CheckTable and no errors have been found. I also have run DBCC CHECKDB and no errors.
Because I also have 3 other different databases, with the same functionality, on the same server which are going well with more than 100 000 records in that specific ...