-107 is normally incorrect SAP username/password.
Please check that user is active, have not changed password lately, have a SAP license and on the User-screen in SAP is not locked.
Also this SAP Note on issues if username contain special chars https://launchpad.support.sap.com/#/notes/2297923
Then in the settings in CRMFO clear the SAP credentials and have the user enter the credentials again (should they have changed)
Should this not work then on the server try to do a DTW Test (https://www.youtube.com/watch?v=mlhaqitA26I) to ensure the DI-API work as intended