Cannot start a new transaction since you are already in a transaction
Sage 50 is holding an open transaction lock and will not let you begin another entry until that lock is released or cleared.
Sage 50 is telling you that, internally, it believes you are mid-entry on a transaction that was never finished or cancelled. The exact message reads:
Cannot start a new transaction since you are already in a transaction.
Despite the wording, you may not actually have a transaction window open on your screen. Sage 50 tracks transaction state at a low level in its database, and if that state was not cleared cleanly — because of a crash, a network drop, or a forced close — the program still thinks the transaction is live and refuses to let you start another.
Close or cancel any open window
Check every taskbar entry and monitor for a Sage 50 window that might be sitting behind another application. An invoice, journal entry, or purchase order that looks dismissed but is actually minimized will hold the transaction lock. Cancel or post the entry, then try your next task.
Sign out and sign back in
If no window is genuinely open, signing out of the company file and signing back in will usually clear the in-memory lock. In a multi-user setup, make sure no other user sharing the company file has a transaction window open that is locking a shared resource.
Restart the Sage 50 application
When a previous session ended abnormally — a power loss, a Windows freeze, or clicking through an error too quickly — the transaction flag can persist in memory even after you sign back in. Closing Sage 50 entirely and relaunching it forces a fresh load and will typically reset that state.
Check for a stuck or damaged company file
If the message persists across restarts and on every workstation, the transaction lock is likely embedded in the company file itself rather than in the current session. This is the point at which the file — not the installation — needs attention. A damaged or inconsistently indexed database can hold phantom transaction locks that no amount of restarting will clear, and continuing to work around the problem risks further corruption.
Our engineers regularly see this when a Sage 50 (or Simply Accounting) database has been subjected to an improper shutdown or a network interruption during posting. If you are at this stage, we can evaluate the file and determine whether the lock can be safely removed or whether the underlying table needs repair work. The cost and turnaround depend entirely on what is inside your file, so we offer a free evaluation and quote before any work begins.