Why can't I find full texts for certain publications in OPS? For example, on Espacenet I get the full text for document EP0714461 but a description retrieval in OPS leads to the message "The requested data could not be found".

Euro-PCT applications (e.g. EP0714461 A1) are not republished by the EPO because they have already been published in an official EPO language (English, French or German) by WIPO. Espacenet retrieves the full text from the corresponding PCT publication, OPS does not.

Thus you can only retrieve bibliographic data for publication EP0714461A1. The full-text document is published only as WO 9534702 A1. The granted EP patent, however, will be published by the EPO, in this case as document EP0714461 B1.