EnDecode | 常见对称加解密，aes，salsa20，chacha20等，一键集成 | Encryption library

I'm stuck with an App that is running on Windows 10 IoT Core. All Classes are working fine, except for the one that is creating a CSV File via JSON and is supposed to send it as an Email.

When the Code reaches the "ReturnToMainPage()" Function the Exception "System.Exception: The application called an interface that was marshalled for a different thread" is thrown.

The "funny" thing is, the Mail is being send and i recieve it but the Program won't switch to back to the Main Page as intendet after sending the Email.

Here is the Code of the Class:

I am hitting the same problem as reported here: utf8_(en|de)code removed from php7? but nothing from any of the ideas have worked.

I've just run:

apt-get upgrade followed by apt-get install php7.0-xmlrpc php7.0-xml and Ubuntu tells me *both is already the newest version.

If I run my simple test script:

echo function_exists('utf8_encode') ? 'Good' : 'Bad';

(Equally if I replace utf8_encode with simplexml_load_file this too returns Bad)

I am constantly seeing "Bad". I'm not running from apache (although it is installed on the server) I am running direct from the command line.

I've also done a reboot and still no progress. PHP Version reports:

7.1.13-1+ubuntu17.10.1+deb.sury.org+1

Which is wierd considering I thought this function was still in at this point?

So my question is how can I get utf8_encode/decode working??