This weekend I tested the current Flatpress 1.1 “Da capo” under PHP 7.4rc6. Unfortunately there were errors, which are visible again with every new page request.
This error occurs in three core files:
Deprecated: Array and string offset access syntax with curly braces is deprecated in…
PHP 7.4 is expected to be released in late November 2019 and I think Flatpress will be able to handle PHP 7.4 in early 2020.