If you receive the Error while invoking AddModifierToTransaction error on the Online Ordering POS Integration app for Aldelo - there is a communication issue between your Aldelo POS server & Orders2me account
You'll need to verify that all items & modifiers are mapped on the Orders2me back-end. You can access this under Settings > POS Settings. You'll want to go through and map all the options that don't have corresponding POS items attached.
Once that's completed, Follow these steps;
Shut down the Online Ordering POS Integration App by clicking Exit on App
Shut down your Aldelo POS (this only needs to be done on the station we're installed on)
Restart both by double clicking the Aldelo POS Integration app on your desktop (this will launch Aldelo as well)
This will establish a new connection & online orders will flow through as normal
**If Aldelo doesn't launch - please check the status of your Aldelo API License