2020-03-23-15-58
If my memory is correct, this issue didn't happen before 2020-03-23
firefox 74.0-2 (happens on other browsers too; possibly in electron app and on mobile devices as well)
found irrevelant during testing the issue on other browsers and operating systems
see above
Image
Image placeholder
tab focused, tab unfocused and tab focused again

2x (for each image that did not load)
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://prod-nginz-https.wire.com/assets/v3/ID&asset_token=TOKEN&forceCaching=true. (Reason: CORS request did not succeed).
I can confirm that the same happens with Wire open in Hamsket 0.52.0 (which identifies as Chrome 73.0.3683) and 0.6.0 (Chrome 80.0.3987). Refreshing the tab with Wire makes images successfully reload. It never happened to me on mobile (Android) as far as I remember.
If this somehow helps with narrowing the problem, this also occurs on the Windows client since last update (3.16.3562 with web version 2020.03.23.1558)
Thanks for all the reports, we are aware of this issue and currently working on a fix. As a workaround it usually helps to switch to another conversation and then back. This might be a bit less annoying than refreshing the tab.
Issue has been fixed for https://app.wire.com/.
Most helpful comment
Thanks for all the reports, we are aware of this issue and currently working on a fix. As a workaround it usually helps to switch to another conversation and then back. This might be a bit less annoying than refreshing the tab.