Unable to save your changes at this time due to Sage Drive lock conflict
The message means Sage Drive thinks another copy of your company file is open, so your changes are being blocked from saving.
When Sage 50 tells you “Unable to save your changes at this time due to Sage Drive lock conflict.”, it almost never means your data is damaged. It means the Sage Drive sync layer believes another copy of your company file, on another machine or in the cloud, currently holds the lock on the file, and Sage 50 is refusing to overwrite it from your side. In plain terms: the software thinks someone else, or another copy of you, is editing the same books right now.
Why it happens
Sage Drive lets a company file be shared between computers by uploading and downloading copies. Only one copy is supposed to be “active” at a time. The lock conflict appears when that handshake breaks down: a second computer opened the file before the first one released it, a sync did not finish before you tried to save, the internet connection dropped mid-sync and left the lock state stale, or someone opened a local cached copy directly instead of going through the Sage Drive flow. Occasionally the lock is simply stuck: nobody else is in the file at all, but Sage Drive still believes someone is.
What to do first
Before anything else, check whether someone genuinely has the file open. Ask around, or check other machines in the office. If someone does, the message is working correctly: let them close the company file, wait for the sync to complete, then save again. Do not keep retrying while they are working, because each attempt can queue another conflicting change.
If nobody else has the file open
Close Sage 50 on every computer that touches this company file, including your own. Give Sage Drive a few minutes to finish any pending upload or download, and confirm the sync status shows current before reopening. Reopen the file through the normal Sage Drive open flow, not by browsing to a cached local copy, and try your change again. In many cases the stale lock clears once every copy has been closed and the sync settles.
If the conflict keeps coming back
Recurring lock conflicts usually mean the sync itself is unhealthy: an interrupted upload, a machine that never fully syncs, or two computers repeatedly fighting over the active copy. At this point, stop making changes on multiple machines and pick one computer to work from until the problem is understood. Make a fresh backup of the company file from the machine with the most recent data before you try anything else, so you have a known-good copy regardless of what the sync does next.
When the file needs professional attention
If the conflict has persisted through several sessions, or if you suspect changes were saved on two machines and you now have two divergent copies of your books, this is no longer a settings problem. Reconciling diverged copies or repairing a company file damaged by interrupted syncing is data work, not troubleshooting, and attempting fixes in place can make the divergence worse. Our engineers handle damaged Sage 50 / Simply Accounting databases directly, and if you have concluded that Sage Drive is more trouble than it is worth, we also convert Sage 50 to QuickBooks.
Next step
Do not keep saving into a file that reports lock conflicts. Take a backup now, note which machine had the most recent entries, and if the message persists after a full close-and-sync cycle on every computer, send us the file for a free evaluation so we can tell you whether the lock state is stale or the data has genuinely diverged.