Word document in Russian whose title translates to instructions for using tserver. The name does not explain what tserver is, so it is probably a guide for a server-side tool used with some repair or programming software, but its exact purpose cannot be confirmed from the title. It opens in Microsoft Word, LibreOffice or any DOCX-compatible editor. Read it before setting up the related software, and note that a translation tool may help if you do not read Russian.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.