View in Browser Plugin - Deprecated: str_ireplace()

PHPserver 8.1, phpList version 3.6.14, ViewBrowserPlugin plugin 2.12.0+20230928
I installed the plugin and inserted the placeholder.
It is correctly replaced with the correct text and its URL, but when I press on the link the browser presents this error in the header and then follows the correct content of the email.
Deprecated: str_ireplace(): Passing null to parameter #2 ($replace) of type array|string is deprecated in /web/htdocs/www.servicekm.it/home/newsletter/admin/plugins/ViewBrowserPlugin/ContentCreator.php on line 126
phpList version 3.6.14
How can I solve the problems?
Thank you

@ubaldoponzio I don’t understand this. The parameter that is being referenced $replace should not be null.

When phplist sends an email, does it show the “powered by” image or “powered by” text?

thank you for your answer
no, no label as you indicated
https://www.servicekm.it/newsletter/lt.php?tid=cUsAUwIFUwBZD05QA1YCGwcPUVcdXF4PBE9WWgdWUVQBVlEABFMdVFlRWgMCVlYbAwhRAR1QU1NRT1ZRDg0aBAsEVwcFBlQJDgIAGgZSUwcBXQ0EHQcCVlFPAAdVAxpVDQUESFYEUwYMUVBTUgoBBw

@ubaldoponzio

This is what my emails show at the end, which is the text version
image

I guess that someone has modified the phplist code to avoid displaying the “powered by” image or text at the end of each email. If so, that change is not compatible with the plugin.
If you are able to reverse that code change or make it in a different way then the error should not occur.
Alternatively modify the plugin code to disable error reporting

file admin/plugins/ViewBrowserPlugin/ContentCreator.php

line 126 should be

    $content = str_ireplace('[SIGNATURE]', $signature, $content, $count);

add this line immediately before, this should stop that warning being displayed

error_reporting(0);

Again thank you for your answers.
I have entered the function you indicated to avoid the error but I will also do a search to solve the problem of the variable with no value to represet them and avoid problems in the future.