I haven't run into the pic problem yet.
And I could swear I've typed the word sandwich before without encountering this.
I'll try to hit Post a few more times and see if something breaks free.
I added the sandwich tag to your other thread.
Right now they system is scanning your text and trying to add tags. That's the easy bit.
The problem is that because of historical problems, i no longer allow members to create tags. 1 of your tags exist in the system. The other does not. So you are getting the error because of the one that does not. Only the system can't tell you which one is the problem.
The easiest solution is to remove very specific ones. And never type in the entire word. If you enter "sandw" you will see all that start with those letters. Now tap on the one you want.
If you find yourself with a "hit" to some of your letters, it's not a hit. It is the system recognising that some members can create tags and it's next move is to try to create that tag (after you add it, and then try to post/reply). It is far easier to use partial words to ascertain what the issue is because a full word may get a single hit and appear in the same manner.
Also the system uses a normal find algorithm, so you may find that your word is in a compound tag "aubergine/eggplant" and typing "eggp" will get a hit on aubergine. That is something the auto match can not handle, so you'll error if eggplant alone is the tag because it thinks you're trying to make a new tag.
Also note that the system often uses such as raspberry because that is how it appears in recipe titles and the auto matching to title needs an identical hit, not a close match.
Finally, if you think a tag is missing, and would be something that is used more than once, use the report button on the thread to request is creation and addition to your thread.