1. "<Product code> Feature not supported error".
This means that you are not using the Plus tier in QuickBooks Online. Please upgrade to it and try again.
2. Customer names with non-latin characters get saved incorrectly or not at all.
When a Quickbooks Online account is set as US account, it accepts only characters from the English alphabet. If the QuickBooks Online account is set as global, it accepts Chinese characters as well in the client name. Please refer to this for details.
3. I have reset my QuickBooks Online account (e.g. using /purgecompany) and synchronized it again with my Megaventory account. The process generates duplicate products.
This is most likely a result of a not full QuickBooks Online account reset due to a bug on its part. See this link for additional information. A temporary workaround would be to log out and back in in order to trigger resetting the account properly.
4. "QuickBooks INSERT Document [Purchase Order #X]. Reason: Invalid Currency for Megaventory Document: PO #Y. Document Id:Z. Document Currency: [EUR], Vendor Currency: [USD] -- Megaventory will try again in a few minutes."
This is an error message that can only appear in accounts that have multiple currencies set up. In these cases, vendors in QuickBooks Online are associated with a specific currency - and that currency cannot be changed (see here about this). When issuing a Purchase Order to this Supplier in Megaventory, it is necessary to choose that specific Vendor currency in the Purchase Order currency drop-down menu.
5. "Failed to enable some or all of the Megaventory Payment Terms in QuickBooks Online"
This is possibly due to having defined Payment Terms in Megaventory which have a longer name than supported in QuickBooks Online. The Payment Terms limit in QuickBooks Online is 31 characters in length.
6. "Cannot connect to Quickbooks Online service. Could not get Quickbooks Service: Unauthorized-401. Refresh the page to try again."
This is possibly due to someone of the users having clicked the 'disconnect' option under the QuickBooks Online icon. Also, every 6 months the authentication expires (from Quickbooks Online) and it needs to be re-activated. Please click the QuickBooks Online icon and re-connect to QuickBooks Online. This action will not synchronize all the previous data again resulting in double entries in QuickBooks Online. Only the items which have not synced will be sent to QuickBooks Online.
7. QuickBooks INSERT Document [Goods Out and Sales Invoice #XX]. Reason: BadRequest: ValidationException was thrown.
This may be due to the document using a number (XX) which has already been used.
8. QuickBooks INSERT Item [XX]. Reason: BadRequest"
This is probably due to attempting to sync your Megaventory account with a new QuickBooks Online account without going through the Initial Sync process first. If the Initial Sync link isn't available, please contact us.