OK. Will restart Firefox with PlugIns reenabled. Then I’ll post the details.
First intermediary result:
NoScript alone seems responsible for impossibility to login, because login was still impossible after disabling Adblock Plus and uBlock Origin. Only after additionally disabling NoScript, login became possible again.
Next, I’ll post, which script-sources I did disable for this forum, and which I did keep enabled. Wait a momment…
2nd intermediary Edit:
After reenabling both, AdBlock Plus and uBlock Origin, while keeping NoScript disabled, login is possible. Therefore, only my NoScript configuration seems responsible. Next, I’ll post NoScript configuration… Wait a moment…
After changing the NoScript-Settings for
“https://discourse.trueos.org”, login became possible, again.
Interestingly, I had to switch to CUSTOM and enable FETCH permissions.
This wasn’t neccessary before on the TrueOS WebSite, and isn’t necessary on other forums.