000377 : The Side type option is invalid with an ArcGIS for Desktop Basic or Standard license.

Description

Buffer's Side type parameter can only be used with an ArcInfo license. Specifying either LEFT or RIGHT will fail with an ArcGIS for Desktop Basic or Standard license.

Solution

To use Buffer's Side type parameter, an ArcInfo license is necessary. If using an ArcGIS for Desktop Basic or Standard license, you only have the option of setting Side Type to FULL. Learn more about Buffer.