Microsoft Dynamics 365 Business Central sync error: "Please try syncing again. If this problem persists for more than 3 hours, please contact Customer Support"

Why the sync error occurs

This error occurs when the sync connection between Cashflow360 and Microsoft Dynamics 365 Business Central has failed.

How to fix the sync error

To resolve this error, disconnect then reconnect the sync.

Disconnect the sync

Select Settings
Select Setup under Sync
Select Disconnect

Reconnect the sync

Select Settings
Select Setup under Sync
Select Connect For Connection URL:
In Microsoft Dynamics Business Central, select the magnifying glass.
Search for Web Services.
Select Web Services.
Select the first url listed in the OData V4 URL column, for object type Page, to open the link in a new window.
In the new window, select Cancel on the sign in popup, then in the url address bar, copy the first part of url up to ODataV4/, including the forward slash. Don't try to copy and paste right from he list in MSDBC as it won't transfer correctly.
Paste the url in the Connection URL field in Cashflow360 sync login info.

For Username (this field is case-sensitive):
In Microsoft Dynamics Business Central, select the magnifying glass.
Search for Users.
Select Users.
Select a user with Business Premium full access.
Copy the User Name.
Paste the User Name into the Username field in Cashflow360 sync login info.

For Web Service Access Key (this field is case-sensitive):
On the user’s record you collected the User Name from in Microsoft Dynamics Business Central, zoom out on your browser until you can see the full access key on the Web Service Access Key field.
Copy the full access key, all the way up to and including the = sign.
- If there is no web services link URL, select the 3 dots next to Web Service Access Key, select Create a key, and be sure to select the option for the key to never expire. Use this new key in the next step.
Paste this in the Web Service Access Key field in Cashflow360 sync login info.
Select the magnifying glass.
Search for Companies.
Select Companies, then copy the company name (not the display name).
Paste this in the Company Name field in Cashflow360 sync login info - must be the exact company name (not display name) listed in MSDBC for the sync to connect.
Select Save.