I get "500 error" error while editing post

@Celil, I recently experienced the same problem — when I attempted to submit:

@@ -1,37 +1,40 @@
-1.	## **Problem**
+#### Problem
 
-	<!-- In the space below this line, describe briefly how the problem appears to a user. -->
+<!-- In the space below this line, describe briefly how the problem appears to a user. -->
 
-	Installing https://kojipkgs.fedoraproject.org//packages/nextcloud-client/3.12.1/1.fc40/x86_64/nextcloud-client-3.12.1-1.fc40.x86_64.rpm (from https://koji.fedoraproject.org/koji/rpminfo?rpmID=37986784) causes neither the button icons nor context menu entries whatsoever to render:
+Installing [`nextcloud-client-3.12.1-1.fc40`](https://kojipkgs.fedoraproject.org//packages/nextcloud-client/3.12.1/1.fc40/x86_64/nextcloud-client-3.12.1-1.fc40.x86_64.rpm) [^1] causes neither the button icons nor context menu entries whatsoever to render:
 
-	> ![Screenshot_20240327_140512|391x500](upload://zYLry4EObChENbAFMLVWHd0V52u.png)
+[^1]: [`koji.fedoraproject.org/koji/rpminfo?rpmID=37986784`](https://koji.fedoraproject.org/koji/rpminfo?rpmID=37986784)
 
-	## **Cause**
+> ![`Screenshot_20240327_140512|391x500`](upload://zYLry4EObChENbAFMLVWHd0V52u.png)
 
-	<!-- If we know what causes the issue, describe that in one or two lines, without getting deeply technical. -->
-	<!-- Link to other posts explaining technical details if it seems useful. -->
+#### Causes
 
-	Not yet known.
+<!-- If we know what causes the issue, describe that in one or two lines, without getting deeply technical. -->
+<!-- Link to other posts explaining technical details if it seems useful. -->
 
-1.	## **Related Issues**
+Not yet known.
 
-	<!-- Replace both instances of NNNN with the bugzilla bug ID in the Bugzilla line below. -->
-	<!-- If there are more than one related bug, copy to new lines for each. -->
+#### Related Issues
 
-	1.	https://bugzilla.redhat.com/show_bug.cgi?id=2271842#c0
-	1.	[quote="Mr. Beedell, Roke Julian Lockhart (RJLB), post:5, topic:109827, username:rokejulianlockhart"]
-		https://github.com/nextcloud/desktop/issues/6594#issue-2213769118
-		[/quote]
+<!-- Replace both instances of NNNN with the bugzilla bug ID in the Bugzilla line below. -->
+<!-- If there are more than one related bug, copy to new lines for each. -->
 
-	<!-- If there are upstream trackers covering this issue, you could link them here too. -->
-	<!-- You may also want to link to related discussions on Ask Fedora. -->
-	<!-- And, if there are similar problems that are NOT this one, note that too, with links. --> 
+-	[`bugzilla.redhat.com/show_bug.cgi?id=2271842`](https://bugzilla.redhat.com/show_bug.cgi?id=2271842#c0)
 
+-	[quote="Mr. Beedell, Roke Julian Lockhart (RJLB), post:5, topic:109827, username:rokejulianlockhart"]
+	[`github.com/nextcloud/desktop/issues/6594`](https://github.com/nextcloud/desktop/issues/6594#issue-2213769118)
+	[/quote]
 
-1.	## **Workarounds**
+<!-- If there are upstream trackers covering this issue, you could link them here too. -->
+<!-- You may also want to link to related discussions on Ask Fedora. -->
+<!-- And, if there are similar problems that are NOT this one, note that too, with links. --> 
 
-	<!-- When the issue is solved, change this to "Solution" and mark a reply, below, with that solution. -->
 
-	<!-- If there are steps users can take to mitigate the problem, list those here. -->
+#### Workarounds
 
-	None yet.
+<!-- When the issue is solved, change this to "Solution" and mark a reply, below, with that solution. -->
+
+<!-- If there are steps users can take to mitigate the problem, list those here. -->
+
+None yet.

…as the new content of discussion.fedoraproject.org/t/109827/1, I observed:

{
  "log": {
    "version": "1.2",
    "creator": {
      "name": "Firefox",
      "version": "150.0a1"
    },
    "browser": {
      "name": "Firefox",
      "version": "150.0a1"
    },
    "pages": [
      {
        "id": "page_1",
        "pageTimings": {
          "onContentLoad": -1,
          "onLoad": -1
        },
        "startedDateTime": "2026-03-17T21:53:04.873+00:00",
        "title": "https://discussion.fedoraproject.org/t/button-iconography-absent-in-nextcloud-client/109827"
      }
    ],
    "entries": [
      {
        "startedDateTime": "2026-03-17T21:53:04.873+00:00",
        "request": {
          "bodySize": 151,
          "method": "PUT",
          "url": "https://discussion.fedoraproject.org/t/109827/tags",
          "httpVersion": "HTTP/2",
          "queryString": [],
          "headersSize": 1800,
          "postData": {
            "mimeType": "application/x-www-form-urlencoded",
            "params": [
              {
                "name": "tags[0][id]",
                "value": "395"
              },
              {
                "name": "tags[0][name]",
                "value": "kde"
              },
              {
                "name": "tags[0][slug]",
                "value": "kde"
              },
              {
                "name": "tags[1][id]",
                "value": "947"
              },
              {
                "name": "tags[1][name]",
                "value": "f40"
              },
              {
                "name": "tags[1][slug]",
                "value": "f40"
              }
            ],
            "text": "tags%5B0%5D%5Bid%5D=395&tags%5B0%5D%5Bname%5D=kde&tags%5B0%5D%5Bslug%5D=kde&tags%5B1%5D%5Bid%5D=947&tags%5B1%5D%5Bname%5D=f40&tags%5B1%5D%5Bslug%5D=f40"
          }
        },
        "response": {
          "status": 500,
          "statusText": "",
          "httpVersion": "HTTP/2",
          "cookies": [],
          "content": {
            "mimeType": "text/html; charset=utf-8",
            "size": 658,
            "text": "<!DOCTYPE html>\n<html>\n<head>\n  <title>Oops - Error 500</title>\n  <meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\">\n</head>\n<body>\n    <h1>Oops</h1>\n    <p>The software powering this discussion forum encountered an unexpected problem. We apologize for the inconvenience.</p>\n    <p>Detailed information about the error was logged, and an automatic notification generated. We'll take a look at it.</p>\n    <p>No further action is necessary. However, if the error condition persists, you can provide additional detail, including steps to reproduce the error, by posting a discussion topic in the site's feedback category.</p>\n</body>\n</html>\n"
          },
          "redirectURL": "",
          "headersSize": 526,
          "bodySize": 1184
        },
        "cache": {},
        "timings": {
          "blocked": 0,
          "dns": 0,
          "connect": 0,
          "ssl": 0,
          "send": 0,
          "wait": 354,
          "receive": 0
        },
        "time": 354,
        "_securityState": "secure",
        "serverIPAddress": "184.105.99.43",
        "connection": "443",
        "pageref": "page_1"
      },
      {
        "startedDateTime": "2026-03-17T21:53:05.743+00:00",
        "request": {
          "bodySize": 103,
          "method": "POST",
          "url": "https://discussion.fedoraproject.org/presence/update",
          "httpVersion": "HTTP/2",
          "queryString": [],
          "headersSize": 1843,
          "postData": {
            "mimeType": "application/x-www-form-urlencoded",
            "params": [
              {
                "name": "client_id",
                "value": "df74222a2ae04283b0bd48d210ba2dab"
              },
              {
                "name": "present_channels[]",
                "value": "/discourse-presence/edit/285884"
              }
            ],
            "text": "client_id=df74222a2ae04283b0bd48d210ba2dab&present_channels%5B%5D=%2Fdiscourse-presence%2Fedit%2F285884"
          }
        },
        "response": {
          "status": 200,
          "statusText": "",
          "httpVersion": "HTTP/2",
          "content": {
            "mimeType": "application/json; charset=utf-8",
            "size": 40,
            "text": "{\"/discourse-presence/edit/285884\":true}"
          },
          "redirectURL": "",
          "headersSize": 1468,
          "bodySize": 1508
        },
        "cache": {},
        "timings": {
          "blocked": 0,
          "dns": 0,
          "connect": 0,
          "ssl": 0,
          "send": 0,
          "wait": 207,
          "receive": 0
        },
        "time": 207,
        "_securityState": "secure",
        "serverIPAddress": "184.105.99.43",
        "connection": "443",
        "pageref": "page_1"
      }
    ]
  }
}

I’ve removed \$\.log\.entries\[\d+\]\.request\.headers from that HAR.

I solved it by removing the kde and f40 tags. Consequently, the problem appears to be that the error message is not sufficiently descriptive.

Tangential

However, all subsequent attempts to modify it:

@@ -38,3 +38,11 @@ Not yet known.
 <!-- If there are steps users can take to mitigate the problem, list those here. -->
 
 None yet.
+
+---
+
+#### Tangential
+
+This post should be tagged, but cannot be:
+
+https://meta.discourse.org/t/i-get-500-error-error-while-editing-post/136500/17?u=rokejulianlockhart
\ No newline at end of file

…fail, with an error that I have encountered elsewhere: