Error warning when saving signature or post edits

I've met with the same error warning while executing two different actions:

1. Trying to save changes to my signature, no matter if it has a link or not.
2. Trying to save a post edit.

The warning I'm referring to has the following text:
The following error occurred:
Your content can not be submitted. This is likely because your content is spam-like or contains inappropriate elements. Please change your content or try again later. If you still have problems, please contact an administrator.

I've met this error in Firefox and in Brave (Chrome engine), with adblockers disabled.
PS: It seems that depending on how, so to speak, you edit the post or the signature, saving might fail or not. Rather strange I must say.

I also have a somewhat related question: how long does the edit button remains available in a post? I've got the impression that it goes away too fast.

 

I undertand, I'll bear with it then. Thanks for the clarification. By the way, maybe you should have this detailed with the forum rules (I don't remember seeing this explained there), so new members have it at hand right when they join Mythic Scribes.