Create a new gallery, add an image, check that image can be inserted. Close app, delete the image file, restart, and the gallery item cannot be inserted again since it looks for the file.
confirm in Version: 6.3.0.0.alpha1+ (x64) Build ID: 63b39fe87644587210214198fb67d6b3fb3343c5 CPU threads: 4; OS: Windows 10.0; UI render: GL; VCL: win; TinderBox: Win-x86_64@42, Branch:master, Time: 2019-05-27_03:06:43 Locale: ru-RU (ru_RU); UI-Language: en-US Calc: threaded and in 6.0.4 too
Please keep blocking on bug 120718 as i may have to update the extension.
I can repro with Version: 4.2.0.0.alpha1+ Build ID: fc8f44e82de4ebdd50ac5fbb9207cd1a59a927e3