System Information
Operating system: Windows-7-6.1.7601-SP1 64 Bits
Graphics card: GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 417.35

Blender Version
Broken: version: 2.80 (sub 60), branch: blender2.7, commit date: 2019-05-07 00:16, hash: rBbfef3bce1a93
Worked: (optional)

Short description of error
Then i use mirror modifier, LoopTools > Circle not work.
After i apply mirror loop tools work correctly.

Thanks!)

ps Re-open file don't help.

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)]