What is the limit for active sessions, and is it shared across transaction types?

The limit is 5 active sessions, and the limit is separate for each form type:

• Each supported form type (Sales Invoice, Sales Order, Estimate, Credit Note, Purchase Order, Purchase Quotation, and Debit Note) has its own set of active sessions, with a maximum of 5.
• Using all available active sessions for one form type, such as Sales Invoices, does not affect the number of active sessions available for Purchase Orders or any other supported form type.