Hi @adrianolavopa,
Thank you for your message.
Tell me please, why do not you write before the support forum? I’m very happy to help you, but a plugin review is not the place for that.
This type of problem can occur for various reasons.
Please read this thread:
https://wordpress.org/support/topic/welcome-to-support-forum-please-read-before-posting-5/
…and write to me in the support forum.
Please also send me some images that you cannot convert. It happens that they have wrong data inside and PHP extension is unable to convert them.
This is certainly a problem that we are able to solve. I will be grateful if you let me help you first and then you add a review. If there was a bug in the plugin, 30.000 other people would report similar problems, and it is not.