Hello AlishaM,
Thank you for your question.
Basically you can select both versions to upgrade your existing installed version, but version 16.0.4 has a completely new GUI and also some of the already known ZAPTEST features were removed:
– The recording option was removed completely, so if you still interested in using this feature please upgrade your ZAPTEST version to 15.1.35.
– Its new GUI allows more friendly accessibility and navigation of ZAPTEST features, such as in ZAPDOC and in Multirun (Which is now named simply as “ZAPTEST”).
– More new features were added, such as:
Saving test’s steps in the CA management tool, getting larger views of the machines being connected to Multirun, fixed existing issues, etc.
Please note ZAP continues to support all ZAPTEST versions even the older ones.
Please contact ZAP for further help.
Thanks,
Sasha