SteveCook I saw something similar on my GivTCP add-on yesterday as well. I had 2.4.9 installed but was being recommended to update to 2.4.3 (i.e. a downgrade), and was getting a server error as you were as well.
I suspect something wrong in the internet was causing that because later on it cleared itself.
2.4.9 is a precursor to going to GivTCP v3.0. At the moment with the issues I’ve had with v3 not reporting my battery data I have gone back to 2.4.9. There is a v3.0.1 out which Rob reports is working but I’m personally holding off until I’m more sure it is fixed.
On your GivTCP log though, on the face of it, you have a few write errors and lots of write success messages. The occasional error is fine, I get them as well, but what doesn’t look right is the repeated writing every 10 seconds to charge slot 1. I don’t think Predbat is doing that (you can check the Predbat log for the same time period to see what it says its doing), but it looks to me more like the write is not working and is being retried automatically by GivTCP. GivTCP does a write and then read afterwards to check the data is there, and so this might possibly be what’s happening - the write works but when the read back is done, the data hasn’t changed, and so givtcp retries after 10 seconds.
Here for comparison is my log from this morning, a read error at 4:30 causing a python error and a battery read error (no data) at 8:04, but commands get written once and don’t repeat as they are in yours.

And I have two inverters so twice as much chance for things to not work
What’s your run loop timer set to in the givtcp settings - something like 20 or 30 seconds (it shouldn’t be too small a value, above 15 is recommended), and check you have ‘raw output’ set to on as well.
This is pointing to a problem with comms to your inverter to me, either the dongle, the inverter itself, or your wifi.
Have a look at this video https://youtu.be/v9a7sDsiK0s and in particular go through the steps to login to your dongle and check what wifi and what wifi strength it is on. Maybe the inverter has connected to a mesh node with poor signal. I have a mesh node in my garage and sometimes I see my inverters are connected to the node in the lounge not the garage - maybe the signal is just too strong for them? Dunno, worth checking your wifi connection from the inverter first before calling GE support