f0cd10388499d445c52a3642a4b9111c5f403b7d
max
  Mon Mar 30 15:17:28 2026 -0700
improving error message when db was not found, refs #37305

diff --git src/hg/lib/cart.c src/hg/lib/cart.c
index 9b48f969e07..6f25457f08f 100644
--- src/hg/lib/cart.c
+++ src/hg/lib/cart.c
@@ -1463,31 +1463,35 @@
 char *db = cartOptionalString(cart,"db");
 
 if ((db == NULL) || startsWith("hub_", db) || sameString("0", db))
     return;
 else
     {
     char *url = genarkUrl(db);
 
     if (url != NULL)
         {
         cartSetString(cart, "genome", db);
         cartAddString(cart, "hubUrl", url);
         cartRemove(cart, "db");
         }
     else if (!hDbIsActive(db))
-	errAbort("Can not find database '%s'", db);
+	errAbort("Can not find database '%s'.<br>"
+                "You can <a href='https://genome.ucsc.edu/assemblySearch.html?q=%s'>search for the genome %s in "
+                "the list of NCBI/INSDC assemblies</a>, then click 'request' when you have found the right assembly "
+                "and enter your email address. We will then make a genome browser and get back to you within a few days",
+                db, db, db);
     }
 }
 
 boolean isValidToken(char *token)
 /* send https req to cloudflare, check if the token that we got from the captcha is really the one made by cloudflare */
 {
     char *url = "https://challenges.cloudflare.com/turnstile/v0/siteverify";
     char *secret = cfgVal("cloudFlareSecretKey");
     if (!secret)
         errAbort("'cloudFlareSecretKey' must be set in hg.conf if cloudflare is activated in hg.conf");
 
     char data[3000]; // cloudflare token is at most 2000 bytes
     safef(data, sizeof(data), "secret=%s&response=%s", secret, token);
     char *reply = curlPostUrl(url, data);