Can not activate plugin

Hello,
no there are no special requirements, actually you’re the first person reporting something like this.

There is a validation process on activation of plugin, but it’s really simple and it should ends up with an error message in case of troubles, so that’s really weird… probably your hosting can not convert to WebP?

Please enable debug log and errors tracking, try to activate it again and let me know, what you can see in the debug.log, but I’m almost sure, there is missing GD or Imagick library on your server, or missing support for Webp in both of them.

It looks like cURL error in configs.php file. There is only one place where ‘error:’ string exists: wp_die( 'error:' . curl_error( $ch ) ); It means that your server does not respond on HTTP request on https://example.com/wp-content/plugins/images-to-webp/tests/test.png. There may be many different reasons why. Replace ‘example.com’ with your host and try to open the URL in browser.

BTW implementation of cURL in the plugin should respect WP filter https_ssl_verify, something like

$ssl_verify = apply_filters( 'https_ssl_verify', TRUE, $test_image );
curl_setopt( $ch, CURLOPT_SSL_VERIFYPEER, $ssl_verify );

I had to add it manually to be able to install the plugin on my local installation.

@janrenn
Ok, thank you, I’ll add this to my plugin ??

@lukasfrompokrok
Can you test this version please?
https://files.kubiq.sk/images-to-webp.zip

Also try to open /wp-content/plugins/images-to-webp/tests/test.png and let me see if you can see small solid color square or 4 squares with red dot in the middle.