<i>Originally by "outdoor_guy". Edited for formatting by "drh"</i> I have the following code: ~~~~~ CListenController::~CListenController() { sqlite3_close(m_db); } bool CListenController::openDB(QString DBPath) { int rc = sqlite3_close(m_db); if (rc != SQLITE_OK) { return false; } m_db = nullptr; sqlite3 *db; rc = sqlite3_open_v2("file:///D:/QTTest/Zeitschriften/GEO_Register.db",&db,SQLITE_OPEN_READWRITE,NULL); if (rc != SQLITE_OK) { return false; } m_db = db; return true; } ~~~~~ In this case got back the rc = SQLITE_CANTOPEN(14) and the DB is not opened When debugging it, the problem seems to appear in sqlite3BtreeOpen(), and there in sqlite3PagerSetPagesize() Strange thing is: When I call the function the following way: ~~~~~ rc = sqlite3_open_v2("GEO_Register.db",&db,SQLITE_OPEN_READWRITE,NULL); ~~~~~ It opens the DB-File (this is the same DB-File) ~~~~~ System: Windows 10, happens both with MSVC 2017 and MinGW. Using the Qt-Framework 5.12.9 SQLite Version: define SQLITE_VERSION "3.33.0" define SQLITE_VERSION_NUMBER 3033000 define SQLITE_SOURCE_ID "2020-08-14 13:23:32 fca8dc8b578f215a969cd899336378966156154710873e68b3d9ac5881b0ff3f" ~~~~~