Language is not recognized after Update to 2.7.1

I read this comment in the file /core/base.php
So I am quite sure your developer doesn’t understand anything about languages or you did not test at all ;=(

“// filter fixing a bug with automatic load_text_domain_from WP didn’t understand yet why this was necessary…
// somehow wp_register_script(which is irrelevant) was triggerring this kind of notice
// Warning: is_readable() [function.is-readable]: open_basedir restriction in effect. File(C:\Domains\website.com\wwwroot\web/wp-content/plugins/C:\Domains\website.com\wwwroot\web\wp-content\plugins\wysija-newsletters/languages/wysija-newsletters-en_US.mo) is not within the allowed path(s): (.;C:\Domains\;C:\PHP\;C:\Sites\;C:\SitesData\;/) in C:\Domains\website.com\wwwroot\web\wp-includes\l10n.php on line 339
// the only solution is to make sure on our end that the file exists and rewrite it if necessary”

I have this settings:

in Settings / General:

language = Deutsch (Sie)

I have installed language fallback plugin, there the defined language is “Deutsch”

german language file is ignored (other plugins work perfectly with that configuration)

when I change to “default language = Deutsch” and language-fallback is “Deutsch (Sie)”, Mailpoet is in German language

there must be something wrong. You can’t force me to use the standard-german-language definition when everything else is working with formal german definition

Next test:

I added de_CH.mo and all other swiss language files to the actual installation

I can activate this language as default language.
MailPoet switches to => English

I activate German as default language
MailPoet switches to => German

I activate Formal German (de_DE_formal.mo) as default language
MailPoet switches to => English

so your plugin does not recognize the language standards in version 2.7.1

it was ok in versoin 2.7

Dear People from MailPoet,

I am waiting for days for a solution of the problem
and I am not the only one

your only reaction is the notice of a duplicated posting, but no answer concerning the bug at all

what is the problem? Don’t you see the bug?
can’t you reproduce it?
I can reproduce it at at least 10 websites where I did not update until now

I really ask you to give support here, I ask politely and on my knees…

what is the problem? Why don’t you give support?

What can I do that you fix the problem????

Same problem.
Any solutions so far?

OK found a solution.
It is in German.

https://www.web266.de/tutorials/wordpress/handbuch-fuer-redakteure/newsletter/mailpoet/bekannte-probleme/spracheinstellung-ab-wordpress-4-3/

@raul_raulus: This is not your topic. If you require assistance then, as per the Forum Welcome, please post your own topic.