Problem

Files Saved down to V7 Format are enabled with Enhanced Precision.

A variable can disable this.
Files created in V8 are enabled with Enhanced Precision.

This capability was added around V7.1 <(>&<)> has been enabled in every version since.
V7.0 <(>&<)> below will not open these files <(>&<)> display the following error message:

Unable to Open Design File.

Product: MicroStation
Version: Varies
Area: Save as V7

Solution

Set/Define the following variable to remove enhanced precision from the V7 file:

Workspace > Configuration>MS_ENHANCEDPRECISION = 1