This is a comment on Blank page after install. 18.04 LAMP, posted by WikiAdmin at 12.12.2019 21:16

View source for Re: Missing BC Math or GMP extension

PHP Fatal error: The **BC Math** or **GMP** extension is missing. The Hashids lib and the URI router is therefore failing. 

The installer indicates whether all required **PHP extensions** are available.


**BC Math** (##php-bcmath##) should be available if you did the following:
apt -y install

Please install **all** required **((/Doc/English/Requirements PHP extensions))**: bcmath, ctype, gd, iconv, json, mbstring, openssl, pcre, spl.
Then try it again.

I suggest you to install already **R6.0.rc1** because this will save you the migration to Unicode later on. R6.0.0 will be out soon.