The mod Quality condenser (1.3.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event quality-condenser::on_configuration_changed
The mod Beacon Rebalance (2.0.3) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event wret-beacon-rebalance-mod::on_entity_cloned (ID 135)
wret-beacon-rebalance-mod/control.lua:79: attempt to index field 'entity' (a nil value)
stack traceback:
wret-beacon-rebalance-mod/control.lua:79: in function <wret-beacon-rebalance-mod/control.lua:76>
stack traceback:
[C]: in function 'clone'
quality-condenser/control.lua:198: in function <quality-condenser/control.lua:178>

I instantly receive this whenever I try to open a world I literally played 40 minutes ago

That is an issue with the wret beacon rebalance mod, it is not handling the entity cloning event properly: https://github.com/wretlaw120/Wretlaw-Beacon-Rebalance/blob/f104950a525b1bb923770f999a1ba8243426285f/control.lua#L79 (in the cloning event the new entity is stored in the variable .destination)

In order to update this mod without triggering the faulty code in that other mod you could deconstruct all of the quality condensers before upgrading.