Operating system: Windows-10-10.0.17134 64 Bits
Graphics card: Intel(R) HD Graphics 530 Intel 4.5.0 - Build 220.127.116.1194
Broken: version: 2.80 (sub 74), branch: master, commit date: 2019-06-19 18:29, hash: rBd30f72dfd8ac
Short description of error
UV Export does not work when "modified" is checked in the export dialog.
Exact steps for others to reproduce the error
- Go to 'Edit Mode' for a mesh object.
- In the UV editor menu bar select UV -> Export UV Layout.
- Give a file name and check 'modified' in the lower left corner.
- Click 'Export UV Layout'.
Result: Red error info appears in the status bar and the objects exists Edit mode.
A screenshot and a simple blend file is attached.