Omeka Admin Page Doesn't Display

Dear Fellow Omeka users,

I’ve recently updated to PHP7 on my server, and ever since the update a very strange thing has persisted: My site displays okay UNTIL I log in as admin. Then, all I get is an empty admin page. Even more bizarre is that if I now (i.e. still logged in) go back to the homepage, that too will fail to display.

After logging in – nothing displayed at all:

I’ve tried reverting to PHP 5.x. I’ve also checked if the required extensions are present, and they are.

[UPDATE]
I’ve found the following error in error_log:

PHP Fatal error: Call to undefined function iconv_strlen() in /home/fabrizoltan/omeka/application/libraries/Zend/Validate/Hostname.php on line 1823

[SOLVED]

For some reason the iconv package had to be manually enabled and PHP recompiled. (Originally phpinfo() showed, that it was compiled with conflicting with and without directives for iconv. Weird.)

Could anybody please help?

Many thanks in advance,
Peter

Before logging in – all seemingly fine: