This error code 30138-6 appeared due to the failed updates in the user feedback. It is also mentioned to be an Outlook issue. The user tried system restoration and put the computer back to an earlier point which again failed with the same error during the next restart.
The conclusion for the causes is failed updates due to the connectivity issues.
This happens with both Office 365 and Office 2013.
Observations for Error Code 30138-6:
As Microsoft enhances the security features and patches on it’s products. This error is found as an update packages failure on a machine.We have tested a computer with a failed update and computer with a successful update.
The test results claim that the errors appeared on system files.
The reason is due to the missing updates for the system files.
Windows 8 listed corrupted files which are not repaired with a SFC SCAN.
SFC Scan is an inbuilt Windows troubleshooting feature to check and repair system files through a
Fix the system file issues at first using sfc scan.
SFC SCAN can be performed using the following link
Finally try to repair the program or reinstall the office program.