QB Issue Resolution:
We received reports about not being able to attach .xlsx file. Our engineers are already working on this to get this fixed.
Please also make sure to remove any extra space before the period when typing a file extension to prevent any error. Otherwise, please call our Phone Support Team so they can add you to the list as one of the affected users.
Resolution for Issue 'Why can’t I attach .xlsx file?' available: Yes (Solved).
Source: Intuit Community forum.
Why can’t I attach .xlsx file?: this issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.
Support for ReportsQuickbooks Repair Pro will resolve it efficiently and affordably. Guaranteed resolution of your issue, or you pay nothing!
Error Recovery for Reports [Canada]
E-Tech is the #1 Quickbooks data migration and Conversion service provider.
Additional Support Options: