Well, the cause of the glitch is localized.
Comparison of the old and new scripts revealed their almost complete identity except for the SQL and PHP options.
The key was the parameter in the "config" file.
Old:
# General Settings
Php_version = 5 # PHP version 5 or 7
New:
# General Settings
Php_version = 7 # PHP version 5 or 7
Total change in the current version of 7 to 5.
Run the script for execution and on the output we have a system free from glitches revealed by me in the process.
There's really one minus.
The glitch exits earlier: it is impossible in ADMINER to connect to the database with a valid password.
A similar experiment conducted on FreeBSD unfortunately ended unsuccessfully.
With the installed version of PHP = 5 everything is installed but the FisionPBX site does not open.
Looked a bit of the installation scripts from FreeBSD, there's a somewhat conflicting selection of packages when choosing version 5 PHP.
I unfortunately did not manage to understand the intricacies of the installation scripts.
Conclusion on the topic.
The authors in the process changed the version of PHP and did not test the previously written applications for the site for compatibility and functioning. If I accidentally caught three glitches, then I think that they are an order of magnitude greater.
There are no working ways for me yet.
You need a working system on FreeBSD.
I think this information will reach developers in some way.
I will wait for the solution of the problem
Thanks to all.