I used Mamp myself until yesterday and haven’t run into this issue yet, with none of the 7.1+ PHP versions (Mamp 5.3/OS X Mojave).
When exactly does this error occur? Any steps to reproduce?
There is a bug report with this problem re. PHP 7.3 https://bugs.php.net/bug.php?id=77260
Seems that a temporary fix would be to set
pcre.jit=0
in PHP.ini according to this SO thread.