Internal Error 500 when importing .csv

[logicalError]

I get an Internal Error 500 when I try to import a simple .csv
I think that it is linked to the .htaccess configuration

# URL rewriting module activation
RewriteEngine on

# URL rewriting rules
RewriteRule ^([a-zA-Z0-9-]*)/([0-9]+)\-([a-zA-Z0-9-]*)\.html(.*)$ product.php?id_product=$2$4 [L,E]
RewriteRule ^([0-9]+)\-([a-zA-Z0-9-]*)\.html(.*)$ product.php?id_product=$1$3 [L,E]
RewriteRule ^([0-9]+)\-([a-zA-Z0-9-]*)(.*)$ category.php?id_category=$1 [QSA,L,E]
RewriteRule ^content/([0-9]+)\-([a-zA-Z0-9-]*)(.*)$ cms.php?id_cms=$1 [QSA,L,E]
RewriteRule ^([0-9]+)__([a-zA-Z0-9-]*)(.*)$ supplier.php?id_supplier=$1$3 [QSA,L,E]
RewriteRule ^([0-9]+)_([a-zA-Z0-9-]*)(.*)$ manufacturer.php?id_manufacturer=$1$3 [QSA,L,E]

# Catch 404 errors
ErrorDocument 404 /404.php

but I do not know how to modify it.
Is there a patch to correct this error?
thanks to everybody.

[Patric]

Moved into the english section