Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce RTX 2080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 430.86
Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: rBf6cb5f54494e
Short description of error
[Please fill out a short description of the error here]
Mirror modifier has default value 0.1 of vertex merge.
it is very bad and confusing value, cause makes problems with precise modelling after APPLY.
In many cases this default value destroyed my model and erases small mesh elements at the border.
IT SHOULD BE 0.0 ( or 0.000000000000....1 - lowest as possible as in previous versions of Blender) by default.
Exact steps for others to reproduce the error
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]
Just use Mirror Modifier.