Hi Antara,
SAP has an PAM guide which can referred to check the supported browsers with BI4.1SP2.
If BI4.1SP2 does not support FF40.0.3 then it would not work for you.
Either you can look for other supported browsers with this BI version or you can also upgrade the BI version to get the support for FF40.0.3.
~SwapnilY