SQLite: Could not connect to database: unable to open database file

I created a database ontime using SQLite Manager for Firefox. Also, I created a table ontime inside this database (see the attached image).

Next I run this code in R:

library(RSQLite)
library(DBI)

sqLiteConnect <- function(database, table) {
  con <- dbConnect(RSQLite::SQLite(), dbname = database)
  query <- dbSendQuery(con, paste("select count(*), tailnum from ontime group by tailnum ", table, ";", sep="")) 
  result <- fetch(query, n = -1, encoding="utf-8")
  dbClearResult(query)
  dbDisconnect(con)
  return(result)
}

result <- sqLiteConnect("D:/sqlite/ontime.sqlite","ontime")

The following error message appears:

Error in .local(drv, ...) : Could not connect to database: unable to open database file

HOW TO FIX THIS ISSUE? I don't know why R cannot find the file. It is located in the specified folder.

Update: However, if I execute this line, then there is another error message:

result <- sqLiteConnect("ontime.sqlite","ontime")

Error in sqliteSendQuery(conn, statement) : error in statement: no such table: ontime

The table exists as it is shown in the image below.