perhaps it’s a strange question, but have you seen the requests of one plugin have conflicts with the codes of others; such that several plugins become disable because of that one?
Yes, this already happened several times here on Meta.
is there any rule of thumbs to follow, so that such situations are avoided as much as possible?
or perhaps a better question, how did you understand which plugin has caused the error?
Don’t install random plugins on a production site
Have a staging environment with similar data from production where you can test before upgrading production
Only install plugins you need. There are several big and active discourse installs plugin free. Of course some instances need a bit of customization but that is a maintenance burden increase that you should be aware.
Read logs, F12 for JS and
/logs for Ruby. The backtrace will tell you where the error is 99% of the time.