It would appear to have been caused by a recent reinstall of SugarSync and inadvertently setting sync on the QB data folder.

Resolution for 'comapny file issue: 'How do I stop Quickbooks 2015 Pro from marking the comapny file as read only every time I close it?' available: Yes.

The comapny file 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 comapny file issue yourself by looking for a resolution described in the article. If it is a complex comapny file issue or you are unable to solve the issue, you may contact us by clicking here or by using other comapny file support options.

For more information about resolving issues related to comapny file in Quickbooks/QBO or to get support for the issue 'How do I stop Quickbooks 2015 Pro from marking the comapny file as read only every time I close it?', click the link below: