I am currently running 2.4.6
Is it quite safe to upgrade to 2.9.2 ?
The answer is hard to give. If you can get a version dated within the last 30 days or so you should be mostly ok. Version 2.9.2 is a development version and carries risks with it. If you find a version of 2.9.2 that is older, I can not recommend upgrading to it.
If you decide to upgrade, make a full offline copy of your data directory and export your settings to the same offline backup. At this point you can run the installer for 2.9.2 and it will update the databases and you should be ready to go.
To get back to 2.4.6 is a bit techie....but instructions are in the forum for the different Operating Systems.
All good !!
I have 2.9.2 running as suggested but can't seem to access bibles even though I appear to have successfully downloaded - any advice ?
Please disregard comment on bibles - I downloaded again and reinstalled - all OK