TFile not compatible in older version

Hi all,
I’m using the root version 5.27/03 to create a TFile but I’m using a an old version of root (the 5.20/00 in the Lyon computing center) to open it and using it.
I get an error message : MyFile.root :not a TStreamerInfo object
I suspect it is a compatibility problem.
Do you knwo what I should do?

This is just a warning message and you should be able to process your file with your old version of ROOT.
In 5.27 we have slightly modified the list of StreamerInfos in the file such that we can more easily support possible future extensions.