diff --git a/addon/webextension/background/senderror.js b/addon/webextension/background/senderror.js
index 83b16069f3..0983c1dcbf 100644
--- a/addon/webextension/background/senderror.js
+++ b/addon/webextension/background/senderror.js
@@ -37,6 +37,9 @@ this.senderror = (function() {
     MY_SHOTS: {
       title: browser.i18n.getMessage("selfScreenshotErrorTitle")
     },
+    EMPTY_SELECTION: {
+      title: browser.i18n.getMessage("emptySelectionErrorTitle")
+    },
     generic: {
       title: browser.i18n.getMessage("genericErrorTitle"),
       info: browser.i18n.getMessage("genericErrorDetails"),
@@ -112,7 +115,9 @@ this.senderror = (function() {
     if (!errorObj.noPopup) {
       exports.showError(errorObj);
     }
-    exports.reportError(errorObj);
+    if (!errorObj.noReport) {
+      exports.reportError(errorObj);
+    }
   });
 
   return exports;
diff --git a/addon/webextension/selector/shooter.js b/addon/webextension/selector/shooter.js
index a8170e3248..cf23709a83 100644
--- a/addon/webextension/selector/shooter.js
+++ b/addon/webextension/selector/shooter.js
@@ -67,12 +67,21 @@ this.shooter = (function() { // eslint-disable-line no-unused-vars
     // isSaving indicates we're aleady in the middle of saving
     // we use a timeout so in the case of a failure the button will
     // still start working again
+    if (Math.floor(selectedPos.left) == Math.floor(selectedPos.right) ||
+        Math.floor(selectedPos.top) == Math.floor(selectedPos.bottom)) {
+        let exc = new Error("Empty selection");
+        exc.popupMessage = "EMPTY_SELECTION";
+        exc.noReport = true;
+        catcher.unhandled(exc);
+        return;
+    }
     const uicontrol = global.uicontrol;
     let deactivateAfterFinish = true;
     if (isSaving) {
       return;
     }
     isSaving = setTimeout(() => {
+      ui.Box.clearSaveDisabled();
       isSaving = null;
     }, 1000);
     selectedPos = selectedPos.asJson();
@@ -82,6 +91,7 @@ this.shooter = (function() { // eslint-disable-line no-unused-vars
     }
     let dataUrl = screenshotPage(selectedPos);
     if (dataUrl) {
+      shot.delAllClips();
       shot.addClip({
         createdDate: Date.now(),
         image: {
diff --git a/addon/webextension/selector/ui.js b/addon/webextension/selector/ui.js
index 7db4b2bfe6..8a5d3de69b 100644
--- a/addon/webextension/selector/ui.js
+++ b/addon/webextension/selector/ui.js
@@ -541,6 +541,10 @@ this.ui = (function() { // eslint-disable-line no-unused-vars
       return false;
     },
 
+    clearSaveDisabled() {
+      this.save.removeAttribute("disabled");
+    },
+
     el: null,
     boxTopEl: null,
     boxLeftEl: null,
diff --git a/docs/error-handling.md b/docs/error-handling.md
index 118c6314c2..d7336eb0dc 100644
--- a/docs/error-handling.md
+++ b/docs/error-handling.md
@@ -105,3 +105,5 @@ Note that any information will be serialized as JSON.  Specifically `undefined`
 If you add `exc.popupMessage = "Something happened"` then that detail will be added.  Be careful about localization here.
 
 Add `exc.noPopup = true` if you don't want the user notified about the error (but the error will still be sent to Sentry).
+
+Add `exc.noReport = true` if you don't want the error reported to Sentry.
diff --git a/locales/en-US/webextension.properties b/locales/en-US/webextension.properties
index 4d7112fa20..d0b5b3e475 100644
--- a/locales/en-US/webextension.properties
+++ b/locales/en-US/webextension.properties
@@ -27,6 +27,8 @@ loginErrorDetails = We couldn’t save your shot because there is a problem with
 unshootablePageErrorTitle = We can’t screenshot this page.
 unshootablePageErrorDetails = This isn’t a standard Web page, so you can’t take a screenshot of it.
 selfScreenshotErrorTitle = You can’t take a shot of a Firefox Screenshots page!
+# Fired when someone makes a zero-width or zero-height selection
+emptySelectionErrorTitle = Your selection is too small
 genericErrorTitle = Whoa! Firefox Screenshots went haywire.
 genericErrorDetails = We’re not sure what just happened. Care to try again or take a shot of a different page?
 # Section for onboarding strings
diff --git a/server/src/servershot.js b/server/src/servershot.js
index d77656be18..974178f4c7 100644
--- a/server/src/servershot.js
+++ b/server/src/servershot.js
@@ -15,16 +15,19 @@ const PNG_HEADER = Buffer.from(PNG_HEADER_BASE64, "base64");
 function assertPng(dataUrl) {
   const urlHeader = "data:image/png;base64,";
   if (!dataUrl.startsWith(urlHeader)) {
+    mozlog.warn("invalid-data-url", {msg: "Invalid data: URL submitted", prefix: dataUrl.substr(0, urlHeader.length + 10)});
     throw new Error('invalid data url');
   }
   // only decode enough to get the header
   // we're lucky that 9 bytes is exactly 12 base64 characters
   const base64Header = dataUrl.substr(urlHeader.length, PNG_HEADER_BASE64.length);
   if (base64Header.length < PNG_HEADER_BASE64.length) {
+    mozlog.warn("invalid-data-image", {msg: "Invalid PNG image submitted", prefix: dataUrl.substr(0, urlHeader.length + PNG_HEADER_BASE64.length)});
     throw new Error('invalid image');
   }
   const header = Buffer.from(base64Header, "base64"); // 9 bytes
   if (!PNG_HEADER.equals(header.slice(0, 8))) {
+    mozlog.warn("invalid-data-image-decoded", {msg: "Invalid PNG image (after base64 decoding)"});
     throw new Error('invalid png');
   }
 }
diff --git a/shared/shot.js b/shared/shot.js
index 1db7f5026a..70da019cdb 100644
--- a/shared/shot.js
+++ b/shared/shot.js
@@ -493,6 +493,9 @@ class AbstractShot {
     }
     delete this._clips[name];
   }
+  delAllClips() {
+    this._clips = {};
+  }
   biggestClipSortOrder() {
     let biggest = 0;
     for (let clipId in this._clips) {