Error 500 occurs when installing modules, why?

Question

CMS

Already repeatedly when trying to install any module, a message appears (at first)

syntax error unexpected token in json at position 0 ftp_nlist.....

After that, I go to the Add-ons Manager and clicked Update.
After some time, the site starts returning error 500, in the logs this is what

[25-Apr-2018 00:30:24 Europe/Moscow] PHP Parse error: syntax error, unexpected 'private' (T_PRIVATE) in /home/s/ser103jb/upgrade33.ru/public_html/catalog/controller/common/header .php on line 2

The site was handed over to me and what they did there before is no longer known. Maybe someone faced similar?

Answer 1

1 error is similar to the standard error when loading modules without ftp setup. Here is the fix

Answer 2

1. If you see along the paths, then this is an error already from the modified file, which has been modified with ocmod or vqmod, the syntax error says that somewhere there is a syntax error with the private function.
Solution: go to this file and find the lines where the error is, find this piece of code in the installed modifiers, disable this modifier, clear the cache, and try to install any module through the standard loader, if everything goes well, then feel free to go edit the code in the file that makes conflict