Can't use 3.4.x with RadioMaster Ranger Micro 2.4GHz about expresslrs

[psfales]

What baud rate (handset hardware settings) and packet rate (Lua script) are you using?
(It's not exactly the same signature, but it sounds similar the issue I had when going from 3.0.x to 3.2.x. See #2010) You may need to try increasing the baud rate or lowering the packet rate

[BRSS73]

Pretty sure. My X12S hangs within 3 seconds of changing the baud rate @ 400K.

Anyway, it doesn't hurt to try to lower the packet rate. I'll take your advice and do it tonight.

[BRSS73]

Lowering packet rate wasn't enough.
I did my long-postponed homework and finally installed the mod.
I can now go @ 400K. Both TX and LUA script are fully functional.

Thanks @psfales for pointing me in the right direction.

[psfales]

I can't remember exactly which release this was, but a few versions later I think it stopped working for me at 400K, and I had to bump it up to the next step (921k?). It may depend on the packet rate.

[BRSS73]

I'm using 115K and 150Hz.
I can't increase the baud rate as my X12S lacks the mod to achieve that (https://blog.seidel-philipp.de/fixed-inverter-mod-for-tbs-crossfire-and-frsky-qx7) and the packet rate is quite low.
I've had the tiny board in my workshop since, at least, one year. I think it's time for me to grab iron, solder paste, thin wires and install it.
Thanks for your help

[psfales]

I would try lowering the packet rate, at least as an experiment to show that this is really the issue. If that helps, then increasing the baud rate (with the inverter mod) would likely help too.

Are you sure that the X12S needs the inverter mod?