**System Information**
Arch linux, i5 sandy bridge
**Blender Version**
Broken: 2.76 (0a2b48e)
**Short description of error**
Appending a group from other file may lead to missing dupli groups when files are mutually dependent.
**Exact steps for others to reproduce the error**
1. unzip {F246016}
2. open a.blend
3. append the group "GroupB" from b.blend
4. notice that the empty with name "GroupA" has no dupli group set while it should point to the group "GroupA" of the current main file.
**Notes**
The setup is as follows:
File a.blend contains an object "Cube" and a group "GroupA" containing this cube.
File b.blend contains a linked instance of "GroupA" from file a.blend and a group "GroupB" containing this instance.
When executing the step above, blender issues a warning:
Warning: LIB ERROR: Data refers to main .blend file: 'GRGroupA' from .../b.blend
I noticed this problem when building a refactoring tool for our blender based project. Unfortunately, the error can't be detected when using the Python API of blender, which can lead to data loss when using such a tool.