I dont know how I got that it just pops up on dropboxes, sometimes while browsing somepages and it will have the same border. It's irritating kindly help.
more examples
another one
either buggy browser behavior or buggy graphic drivers behavior
try to disable hardware acceleration in chrome flags and see if it helps
>chrome://flags
you can also try another browser, like firefox, and see if it has the same or similar issue, in that case change your graphic card drivers, either update to the latest version or rollback to a version that does not present the issue
>>329264
post your full browser window stupid
you probably have a document inspector turned on