Lucas, try to increase interactive_timeout' in my.cnf  file. Or contact your hosting provider support team to assist you with that. 

Then try to reproduce the steps before this issue occurred and check if the issue persists. 

Ho Ross, where I can find this file my.cnf???

This is what my provider answered me ::

__________________________________________________

Please be informed that the error message that we provided was taken/seen in the error_logs of the domain, when the website is/was showing an internal server error, the error message appears in the error_logs.Refer below for the error:+++++++++++++++++++++++++++++++++++++++[13-Mar-2015 16:11:44 Europe/Rome] PHP Parse error: syntax error, unexpected T_ENCAPSED_AND_WHITESPACE, expecting ')' in /home/../ow_pluginfiles/base/lang_6.php on line 4581

[14-Mar-2015 10:37:17 Europe/Rome] PHP Fatal error: Call to undefined method OW_HtmlDocument::getScripts() in /home/../ow_system_plugins/base/controllers/console.php on line 21
++++++++++++++++++++++++++++++++++++++
The error indicates that there is an issue with the said script that is shown above and that is causing the internal server error.Kindly double check the script.
Also we have already checked the server and there are no issues with the network nor with the server.

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PLEASE NEED HELP. THANKS LUCAS

Contact your hosting provider to locate your my.cnf file on the server or check the search results: https://www.google.com/?gws_rd=ssl#q=where+to+find+my.cnf+file

as to this error: PHP Parse error: syntax error, unexpected T_ENCAPSED_AND_WHITESPACE, expecting ')' in /home/../ow_pluginfiles/base/lang_6.php

check the search results on the forum: http://www.oxwall.org/forum/section/2/search?&q=unexpected%20T_ENCAPSED_AND_WHITESPACE

please do the search before posting anything on the forum

As to this error: PHP Fatal error: Call to undefined method OW_HtmlDocument::getScripts() in /home/../ow_system_plugins/base/controllers/console.php on line 21

Do you have cloudflare enabled on your website?

Hi ross, Thank you for your fast reply.

I have read all your answers regarding the first error  and I have checked the error (T_ENCAPSED_AND_WHITESPACE..) every thing seems good on my file (lang_6.php)  the file is not corrupted or missing (') ,..etc.  
On our website, yes the cloudflare is enabled automatically within the hosting but I did not installed any plugin related to cloudflare. 

Lucas, please provide the screenshot of the end of the file lang_6.php. 

As to the cloudflare within your hosting - is it possible to disable it for your server specifically for some time and check if this issue:

As to this error: PHP Fatal error: Call to undefined method OW_HtmlDocument::getScripts() in /home/../ow_system_plugins/base/controllers/console.php on line 21

persists

Hi ross again thank you for your fast reply. i attached the end of my file lang_6.php

regarding the cloudflare i will ask my provider to disable it and after i tell you.

thanks ross for your reply.

Lucas, do you have dev mode enabled on your website in the meantime?

make sure you have not reached your server limits?

Keep us updated.