The problem during installation happens when the hashes are calculated:
This part of code causes by this:
microtime() * mt_rand()
It happens because microtime() returns value
0.91890200 1527509315 which contains space and this space makes multiplying crash.
What can be done:
str_replace(' ', '', microtime()) or something else.
I can try to prepare PR if it's possible for you to accept it.