Hi.
First of all, you have the same issue as the topic creator and you already posted your problem in this topic. Which was perfectly right. I dont get why you descided to delete your post and start a new topic with the exact same error message and problem. So I moved it back again. Please do not open new topics for already existing issues. The topic author might benefit from the information gained out of your problem, and others will have all information in one topic.
Second: although I dont know what might cause your I/O error, you can try to access your vault directly online on pCloud and try to delete your files directly online. Maybe the sync client does then also delete the local files as well.