Fields from 1.7.10 decompiled mod doesn't work

[Yagur]

Decompiled the old mod, functions like field_76421_d (moveSlowdown), field_77990_d (stackTagCompound) and others give an error in the compiler, but if you write them with normal names (moveSlowdown and stackTagCompound), the compiler does not issue errors, but after export they are still there -  field_77990_d cannot be resolved or is not a field and field_76431_k cannot be resolved or is not a field

How can I fix this?

Edited September 23, 2021 by Yagur

[Luis_ST]

1.7 is no longer supported on this forum.
Please update to a modern version of Minecraft to receive support.