After the creation of the fxt-file in ..testerhistory check (and set) this (all) fxt-file(s) as write-protect!
Otherwise MT4 will delete the fxt-file and tries create its own fxt-file – which might have the size 0 which causes the Error message: “no data for testing”.
Fi this wasn’t the problem try to start mt4 itself (don’t launch by Tickstory) and start the strategy tester.
You’ll get the spread of the start.tester field no real spread and the volume has absurd numbers.
The first question is whether you exported the FXT into the location that MT4 is looking? Make sure the FXT exists in the specified location before starting the back-test.