Occasionally when I upload photos to a gallery, my site will go down with an internal error. It only happens when I upload photos through this plugin. If I replace the htaccess file with an earlier version the site will come back up. But then will go down later with another upload of photos.

This is the code that allows the website to work correctly
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

But this is what it gets changed to while uploading photos
# BEGIN WordPress<<IfModule mod_rewrite.c>RRewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

What could be causing this? Any help is very much appreciated, it is hard to use a website that keeps crashing. Thanks.