I have issues with the Gallery App since Updating from NC11 to NC12_RC4.
Error gallery Exception: Preview generation has failed 2017-08-01T10:07:20+0200
Error PHP file_get_contents(//data/appdata_50769f0c76c51/preview/17218/2048-1536-max.png): failed to open stream: No such file or directory at //lib/private/Files/Storage/Local.php#209 2017-08-01T10:07:20+0200
More details:
=> NC11 to NC12_RC4: Preview files in Gallery Module are broken