Error 524 comes from CloudFlare:
It would occur if your server or the plugin did not respond before an HTTP timeout occurs. This could happend due to any number of reasons. Disable cloudflare to see what the problem is:
1. What do you mean by “When i send wallet 5.x”? Are you uploading the plugin zip file from your computer? You can also install 5.0.18 from wordpress.org.
2. When exactly does the timeout occur? When you first install the plugin? When you activate the plugin? When you visit a particular page or click a button?
3. What is written in the PHP error log at the time when the timeout occurs?
You should probably not install a release candidate for a live exchange. Better to wait until I do the proper 6.0.0 release, which I will do in a few days if no more problems arise. Once your 5.0.18 installation works, you can then upgrade to the stable 6.0.0 release, when it is released.
If you are not planning to open your exchange again until a few days later, then it’s OK to go straight to an RC release, and the transition to the stable 6.0.0 plugin will be a simple matter of updating the plugin.
Hope this helps. Good luck.
Please let me know the answers to the above questions, or if you have any questions about the release schedule.