The query below gives some useful information about tables in your database, it will show table names, row counts, storage size and so on. It proved useful to me when searching for the cause...
Category: SQL Server
Microsoft SQL Server is a relational database management system developed by Microsoft. As a database server, it is a software product with the primary function of storing and retrieving data as requested by other software applications which may run either on the same computer or on another computer across a network (including the Internet).
Microsoft markets at least a dozen different editions of Microsoft SQL Server, aimed at different audiences and for workloads ranging from small single-machine applications to large Internet-facing applications with many concurrent users.
SQL Server uses as its primary query languages T-SQL and ANSI SQL