Internal Server error

I am getting this error on clicking on Download on the file I am trying to create:

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, root@localhost and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Apache/2.2.15 (CentOS) Server at http://www.simonsays.org.uk Port 443

I have asked 34sp who host the website and they have found this error that they think might be something to do with the .htaccess file

[Mon Jun 08 11:33:25 2020] [alert] [client 86.143.50.162] /var/www/vhosts/simonsays.org.uk/httpdocs/wp-content/uploads/dae-uploads/.htaccess: <IfModule takes one argument, Container for directives based on existance of specified modules, referer: https://www.simonsays.org.uk/?__wpdmlo=10103

Can you help?

Hi, The Site URL is https://www.simonsays.org.uk/
The error occurs when running the only Download file I have setup https://www.simonsays.org.uk/download/primary-school-bereavement-support-group-guide/
Is that enough info?

Hi, I can see that it works as you have set it up but I want force users to login to download the file. I have been trying to get the login and register functions to work but when the modal login is ticked I don’t see a complete entry screen. I then want it to continue to download the file. I assumed this would work automatically without me having to do any coding. Is that not correct? I am not very technical so am struggling. Are you able to help?