Updates: BTC Pay doesn't seem to work and blockchain reorganisation at block 328198 issue

1. It seems BTC Pay doesn't seem to work so some caution is advised for those who want to sell BTC on the DEx (in exchange for XCP or whatever) as it may not be able to complete (which may mean the DEx 1% fee would be spent in vain).
*If* BTC Pay does not work for you, it's recommended to send some to your favorite centralized exchange and buy XCP or other asset there, then send it back to Counterwallet because BTC Pay may not be fixed:
Other assets (XCP, etc.) can be traded normally on the DEx.

A guide for BTC trading on the DEx from CLI has been posted for those who feel up to the task:
In order to use counterpartyd you need to install Counterparty on your system and download the bitcoin blockchain which can take a day or more. 
How to install Counterparty:

2. Blockchain reorganisation at block 328198 - the issue has been spotted and fixed:
Since the fix isn't in master or develop branch yet, until that happens it can be installed manually.

Here's how to do that if you're on v9.45.0 already. 
First, make a backup or whatever you want to backup (e.g. wallet, c:\\counterpartyd_build)
On Windows, copy this file:
to C:\\counterpartyd_build\\dist\\counterpartyd\\lib\\blocks.py (on Linux ~/counterpartyd_build/dist/blocks.py; first backup the original file if you want)
And copy this file:
C:\\Users\\YOUR_USERNAME\\counterpartyd.py (on Linux, ~/counterpartyd_build/dist/counterpartyd/counterpartyd.py; backup the original file if you want and chmod this file with 775)

Then run counterpartyd. If you get a weird error like the one in counterpartyd issue #385, stop it, then roll back to the block where it gets stuck:
counterpartyd rollback 326734
This could take 20 minutes - you have to let it finish on its own. Then start counterpartyd again.
counterpartyd server

If you're not on v9.45.0 yet, your mileage may vary. In that case - depending on your tolerance for downtime - you could get "develop" branch of 9.45.0 (https://github.com/CounterpartyXCP/counterpartyd/tree/develop), install it, get the above 2 files and see whether that helps.
Note that there's another issue on v9.45.0.
It is better to not upgrade to v9.45.0 until the current issues are solved or until block 330000 (now it's 328210).