URLs in the form https://archive.org/details/texts?and[]=Alfred+Cooper+Fryer&sin= are valid, but are rejected by Wikidata as

URLs are not allowed to contain certain characters like spaces or square brackets

While it is possible to encode the square brackets, so the URL takes the form https://archive.org/details/texts?and%5B%5D=Alfred+Cooper+Fryer&sin= it is not reasonable to expect lay users to know this.

If this cannot be fixed, or as an interim measure, the error message should mention encoding.