Copy from quotation: Unhandled exception

Hi there.

Some informations first:

SAP Version: SAP Business One V9.0 PL 11

SQL Version: SQL Server 2008 R2

Addons: Coresuite addon 4.36.20465

There is an error when using the "copy from" function in sales order (not every time but often):

1. Open new sales order.

2. Choose customer (CardCode).

3. Click "Copy From" --> Quotation.

4. Choose quotation.

5. Choose items and freight by dialog.

6. Click "Finish"

Now, following error occurs (see also attachment):

"SAP Business One has encountered a Problem and Needs to Close.

Diagnostic file will not be created.

.....

SAP Channel Partner Portal > Login > Solution > SAP Business One > Support > Support Self-Help Library > Performance"

I just checked all the possible Performance issues, but the error still occurs.

Does anybody have an idea whats the cause of this error?

Thanks for every response.

Best regards

Rafael