Warning: fopen Cannot modify header information

Hello,
I just installed the new version of WordPress in French at my host under Apache and php7.0. Then I installed the plugin “Meeting” but as soon as I activated, I have several errors and warning in the administration that does not leave me the choice to administer my website. Here are the errors displayed thank you for helping me.

Warning: fopen(/…/public_html/wp-content/plugins/rencontre/inc/dbip-country.csv): failed to open stream: Permission denied in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 289

Be aware that all the wp-content folder has permissions set to 755 and these files 664
Can you tell me what’s going on?

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fwrite() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 293

Warning: fclose() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 296

Warning: file_get_contents(/…/public_html/wp-content/plugins/rencontre/inc/dbip-country.csv): failed to open stream: No such file or directory in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 297

Warning: fopen(/…/public_html/wp-content/plugins/rencontre/inc/dbip-country.csv): failed to open stream: No such file or directory in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 298

Warning: fgets() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 311

Warning: fclose() expects parameter 1 to be resource, boolean given in /…/public_html/wp-content/plugins/rencontre/inc/patch.php on line 345

Warning: session_start(): Cannot send session cache limiter – headers already sent (output started at /…/public_html/wp-content/plugins/rencontre/inc/patch.php:293) in /…/public_html/wp-content/plugins/rencontre/rencontre.php on line 277

Warning: Cannot modify header information – headers already sent by (output started at /…/public_html/wp-content/plugins/rencontre/inc/patch.php:293) in /…/public_html/wp-admin/includes/misc.php on line 1116

Warning: Cannot modify header information – headers already sent by (output started at /…/public_html/wp-content/plugins/rencontre/inc/patch.php:293) in /…/public_html/wp-includes/option.php on line 919

Warning: Cannot modify header information – headers already sent by (output started at /…/public_html/wp-content/plugins/rencontre/inc/patch.php:293) in /…/public_html/wp-includes/option.php on line 920