After the update from 3.3.13 > 3.3.14 it is no longer possible to check the version numbers.

There must be something wrong in file_downloader.php. If I overwrite this with a file from 3.3.13, there are no problems.

fsockopen and/or allow_url_fopen is enabling.

https://www.phpbb.com/community/viewtopic.php?p=16040512#p16040512

Failed to obtain latest version information.

The operation could not be completed because the fsockopen function has been disabled or the server being queried could not be found.