QuickBooks error 15106 is typically displayed when attempting to update QuickBooks Desktop, but the update program can't be opened or stopped. This error might indicate the presence of antivirus software viewing the update as a threat. Another possibility is if the user isn't logged in with administrator rights, restricting the ability to modify specific system files. Resolving this issue may involve disabling the antivirus temporarily or ensuring the user has the correct administrative privileges.
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