You have created Request with Fulltext functionaliy. When searching via fulltext field you get no search results.
Fulltext search for Request since DocuWare Request is generated from fulltext information stored in _Page table of a file cabinet. But this table is filled with Fulltext information since DocuWare 6 only. All Documents that have been stored in DocuWare 5 have no entries in this table and are therefore not considered in Fulltext search.
When you need Fulltext search in Request you have to reset Fulltext for required file cabinets. This results in filling also the _page table with the necessary informations. When creating a new Request the Fulltext informations are used. Fulltext search is showing the correct results.