This table is already in use by...

This error message comes up when you try to access the table which is open and being modified by another POS user. It's restricted in unTill Air to modify the same table from two different devices at the same time in order to prevent possibly linked to this issues and misunderstanding.

Let's take a look at the image below to sort out when the notification 'This table is already in use by...' appears and why.

When table 12 is open and being modified by a user on one device (e.g., the tablet in the image), another user (using the phone in the image) will receive a notification that this table is already in use and cannot be opened. Therefore, the second user will not be able to open and modify table 12 unless the first user end modifying the table.