How to fix "curl 77 error setting certificate verify locations: CAfile *filePath* CApath: *CApath*" error?

Question

PHP

Good afternoon.
Configuration:
OS: Debian
Language: php 5.6
When trying to send a request from php to https, the following error occurs:
"curl 77 error setting certificate verify locations: CAfile *filePath* CApath: *CApath*"
On the Internet they write:
1) make sure that the certificate is valid - it is valid
2) Check if there is access to it - yes, it works file_exist
3) Try to ask the server not to check the certificate - it did not help, the error "certificate was not transferred" occurs
4) Set permissions to 777 - also did not help
5) Install the package "ca -certificates" to the server - it's already installed.
6) Specify the type of certificate - indicated
7) Transfer the certificate to the *CApath* folder - transferred
Tell me, can anyone come across, what else could be the problem?
UPDATE:
8) I noticed that if you specify a deliberately false path to the certificate, then the error remains.
9) Changed the certificate from .cer to .pem, with the correct path to the file, the error "51 SSL: couldn't get peer certificate!"

Answer 1

The issue was resolved, the error was not on our part)