Can't get in

Your VMX system only opens for computers and phones it recognizes. When it doesn't recognize the one you're using, it sends you to a page headed Access that shows your internet address and a Try again link.

That page is not an error and nothing is broken. It means this browser has no access rule yet, or the rule it was using has stopped matching. The fix depends on where you are and who else is affected, so start with the section below that describes your situation.

Fixing any of these takes someone who can still get in, on Admin → Access. Viewing that page needs the 👁️ Perm's admin permission and changing anything on it needs ✏️ Perm's. See Access for what each field does.

Nobody at the store can get in

If every computer at the store hit the Access page at roughly the same time, your store's internet address almost certainly changed. Internet providers hand out these addresses on a lease, and the lease can change when the provider renews it, when the modem or router is replaced, or when you switch providers. Your network access rule still lists the old address, so nothing at the store matches any more.

To fix it, someone needs to get in from a device that still works — commonly a manager's phone or laptop with a personal sign-in link, which keeps working because it doesn't depend on the store's address. Then:

From a computer at the store, search the web for "what's my IP address" and note the number it reports.
On Admin → Access, edit your store's network rule and put that number in IPv4 CIDR.
Save, then reload VMX on any store computer.

If no one has a working way in, email help@vmxllc.com with the address shown on the Access page and we'll restore access.

One computer at the store can't get in, but the others can

When the rest of the store is fine, the problem is that one machine's connection rather than the store's access rule.

Check which network it's on. A computer on a guest network, a separate wireless network, or a phone hotspot leaves the building by a different route than the rest of the store, so the store's network rule doesn't cover it. Move it onto the same network the working computers use.
On a register, check for a backup connection. Registers with a cellular or secondary internet backup can quietly fall over to it when the main connection drops. The register keeps working in every other respect but now reaches the internet by a different path, so it stops matching the store's rule. Restoring the main connection restores access.
Check that it isn't a private or incognito window. A private window doesn't keep anything from a previous visit, so a sign-in link has to be opened again in that window each time.

You're away from the store

The store's network rule only covers people physically on the store's network. Working from home, from a phone on cellular data, or from anywhere else needs a personal sign-in link of your own.

Ask someone with access to Admin → Access to create one for you and send it over. On the row for your rule, the URL column has buttons to email the link, show a QR code for it, or copy it. See Access for the full procedure.

Open VMX using that link. Save the link itself as your bookmark or home-screen shortcut. If you bookmark the page you land on afterward instead, the bookmark won't carry your sign-in with it, and it will stop working after a few days.

Three things stop a link that used to work:

It expired. Access rules can be given an expiration date in the Expires field. Once that date passes, the link stops working.
It was turned off. The Enabled setting on the rule can be switched off without deleting the rule.
You bookmarked the wrong address. If you saved a bookmark from the address bar after signing in, the bookmark doesn't include your sign-in. It appears to work for a few days and then starts showing the Access page. Go back to the original link you were sent and bookmark that instead.

Anyone with access to Admin → Access can check Expires and Enabled on your rule, and re-send your link from the URL column.

A new phone, tablet, or computer

A new device has never been recognized, even if it belongs to someone who already has access on another device. Open the sign-in link on the new device once, then bookmark that link or add it to the home screen. If the person doesn't have their link handy, it can be re-sent from the URL column on Admin → Access.

Still stuck

Email help@vmxllc.com. Include the internet address shown on the Access page, whether you're at the store or somewhere else, and whether anyone else is affected. Those three details are usually enough for us to sort it out without any back-and-forth.