diff --git a/copyparty/web/up2k.js b/copyparty/web/up2k.js
index 7676caa2..1e3b92ae 100644
--- a/copyparty/web/up2k.js
+++ b/copyparty/web/up2k.js
@@ -14,17 +14,19 @@ function goto_up2k() {
 
 // chrome requires https to use crypto.subtle,
 // usually it's undefined but some chromes throw on invoke
-var up2k = null;
-var sha_js = window.WebAssembly ? 'hw' : 'ac';  // ff53,c57,sa11
+var up2k = null,
+    sha_js = window.WebAssembly ? 'hw' : 'ac',  // ff53,c57,sa11
+    m = 'will use ' + sha_js + ' instead of native sha512 due to';
+
 try {
     var cf = crypto.subtle || crypto.webkitSubtle;
     cf.digest('SHA-512', new Uint8Array(1)).then(
         function (x) { console.log('sha-ok'); up2k = up2k_init(cf); },
-        function (x) { console.log('sha-ng:', x); up2k = up2k_init(false); }
+        function (x) { console.log(m, x); up2k = up2k_init(false); }
     );
 }
 catch (ex) {
-    console.log('sha-na:', ex);
+    console.log(m, ex);
     try {
         up2k = up2k_init(false);
     }
@@ -952,7 +954,7 @@ function up2k_init(subtle) {
 
             bpend += cdr - car;
 
-            reader.onload = function (e) {
+            function orz(e) {
                 if (!min_filebuf && nch == 1) {
                     min_filebuf = 1;
                     var td = Date.now() - t0;
@@ -962,6 +964,9 @@ function up2k_init(subtle) {
                     }
                 }
                 hash_calc(nch, e.target.result);
+            }
+            reader.onload = function (e) {
+                try { orz(e); } catch (ex) { vis_exh(ex + '', '', '', '', ex); }
             };
             reader.onerror = function () {
                 alert('y o u   b r o k e    i t\nerror: ' + reader.error);
@@ -1050,7 +1055,7 @@ function up2k_init(subtle) {
             st.todo.handshake.unshift(t);
             tasker();
         };
-        xhr.onload = function (e) {
+        function orz(e) {
             if (t.busied != me) {
                 console.log('zombie handshake onload,', t);
                 return;
@@ -1090,6 +1095,7 @@ function up2k_init(subtle) {
 
                 if (response.name !== t.name) {
                     // file exists; server renamed us
+                    console.log("server-rename [" + t.name + "] to [" + response.name + "]");
                     t.name = response.name;
                     pvis.seth(t.n, 0, linksplit(t.purl + t.name).join(' '));
                 }
@@ -1194,6 +1200,9 @@ function up2k_init(subtle) {
                         (xhr.responseText && xhr.responseText) ||
                         "no further information"));
             }
+        }
+        xhr.onload = function (e) {
+            try { orz(e); } catch (ex) { vis_exh(ex + '', '', '', '', ex); }
         };
 
         var req = {
@@ -1238,7 +1247,7 @@ function up2k_init(subtle) {
         xhr.upload.onprogress = function (xev) {
             pvis.prog(t, npart, xev.loaded);
         };
-        xhr.onload = function (xev) {
+        function orz() {
             if (xhr.status == 200) {
                 pvis.prog(t, npart, cdr - car);
                 st.bytes.uploaded += cdr - car;
@@ -1258,6 +1267,9 @@ function up2k_init(subtle) {
                         (xhr.response && xhr.response.err) ||
                         (xhr.responseText && xhr.responseText) ||
                         "no further information"));
+        }
+        xhr.onload = function (xev) {
+            try { orz(); } catch (ex) { vis_exh(ex + '', '', '', '', ex); }
         };
         xhr.open('POST', t.purl + 'chunkpit.php', true);
         xhr.setRequestHeader("X-Up2k-Hash", t.hash[npart]);
diff --git a/copyparty/web/util.js b/copyparty/web/util.js
index e4563fc0..a354a1d3 100644
--- a/copyparty/web/util.js
+++ b/copyparty/web/util.js
@@ -11,16 +11,6 @@ var is_touch = 'ontouchstart' in window,
 
 
 // error handler for mobile devices
-function hcroak(msg) {
-    document.body.innerHTML = msg;
-    window.onerror = undefined;
-    throw 'fatal_err';
-}
-function croak(msg) {
-    document.body.textContent = msg;
-    window.onerror = undefined;
-    throw msg;
-}
 function esc(txt) {
     return txt.replace(/[&"<>]/g, function (c) {
         return {
@@ -37,7 +27,7 @@ function vis_exh(msg, url, lineNo, columnNo, error) {
 
     window.onerror = undefined;
     window['vis_exh'] = null;
-    var html = ['<h1>you hit a bug!</h1><p>please screenshot this error and send me a copy arigathanks gozaimuch (ed/irc.rizon.net or ed#2644)</p><p>',
+    var html = ['<h1>you hit a bug!</h1><p>please send me a screenshot arigathanks gozaimuch: <code>ed/irc.rizon.net</code> or <code>ed#2644</code><br />&nbsp; (and if you can, press F12 and include the "Console" tab in the screenshot too)</p><p>',
         esc(String(msg)), '</p><p>', esc(url + ' @' + lineNo + ':' + columnNo), '</p>'];
 
     if (error) {
@@ -47,9 +37,13 @@ function vis_exh(msg, url, lineNo, columnNo, error) {
                 html.push('<h2>' + find[a] + '</h2>' +
                     esc(String(error[find[a]])).replace(/\n/g, '<br />\n'));
     }
-    document.body.style.fontSize = '0.8em';
-    document.body.style.padding = '0 1em 1em 1em';
-    hcroak(html.join('\n'));
+    document.body.innerHTML = html.join('\n');
+
+    var s = mknod('style');
+    s.innerHTML = 'body{background:#333;color:#ddd;font-family:sans-serif;font-size:0.8em;padding:0 1em 1em 1em} code{color:#bf7;background:#222;padding:.1em;margin:.2em;font-size:1.1em;font-family:monospace,monospace} *{line-height:1.5em}';
+    document.head.appendChild(s);
+
+    throw 'fatal_err';
 }