Beta viewer hanging



I saw a similar post to this about the viewer hanging on files that were “too large”, but I have had problems with the viewer being unresponsive for any size of file. That will typically result in:

Before this message appears the viewer won’t allow me to scroll or select text to highlight. As well as that, I can’t select any menu items. I Just started having this problem yesterday and I’m not sure what changed. Any ideas?

It seems like it could be a syncing problem. The syncing dot in the top left is continuously flashing. However, in the Paperpile app the Google Drive sync is functioning without any problems. This problem has also persisted over several sessions opening and closing the Chrome browser (this seems to be in agreement with the troubleshooting instructions here).

Edit 2
I am now pretty sure it is based on trying to sync to Google Drive (the problems occur when the dot starts flashing). And a couple of times (out of many) I have gotten an error about the file being changed outside of Paperpile. But again, this has been occurring over multiple sessions.

Edit 3
I restarted the browser, and turned off the automatic sync and seemed to have good performance until I tried to sync using ctrl-s. This resulted in laggy performance, followed by an unresponsive page prompt (like shown above). Selecting Wait does not work. The dot keeps on flashing.

MetaPDF is very slow

Thanks for helping us debugging this issue. What’s the file size of the PDF you are trying to edit/sync?


The files vary in size. Some ~200kB and others ~2MB.

I should also note that this has happened at two locations (home and work), so I don’t think the internet connection is the problem either.


Here is a link to one of the files here. I just marked up a single line and the editor lagged for about 30-45 seconds. When I say “lagged” I mean that scrolling was very slow/unresponsive for that period of time, and the flashing dot was active during that time.


It also seems that if I have two .pdfs open whilesaving a .pdf in one viewer the other second viewer becomes unresponsive.

I should note that I am mentioning these things because I didn’t previously have problems. It seems like something must have changed around the middle of last week.


This file1.12MB and has been trying to sync for several minutes. During this time the viewer/editor is basically useless, it allows scrolling after around 20-30 seconds of lag.

So, it has now been around a half an hour or so that the dot has been flashing and the editor has been unresponsive for the above file. Here are a couple of observations. I close the other tabs with .pdfs open, it had no effect. However, when the viewer/editor is lagging (i.e. I scrolled or highlighted and am waiting for several seconds) it seems that if I move the mouse over a different tab the editor becomes responsive again. Let me explain using three examples:

  • I try to select the file menu but nothing happens, I move my mouse to hover over the address bar or another tab, and the menu appears
  • I try to scroll the .pdf page but nothing happens, I then move my mouse as stated in the previous bullet and the page scrolls
  • I try to select text to highlight but nothing happens, move the mouse and text is selected
  • Press h to highlight the selected text but nothing happens until the mouse is moved as stated above

Hopefully this helps in troubleshooting. This is pretty disruptive to my work.

I just opened the developer tools and everything just fixed itself… not sure why. The dot stopped flashing and the editor became responsive.

Also, the chrome tab that had meta-pdf open was using 30% CPU for that ~ half an hour period that I mentioned above.

Maybe the developer tools thing was a fluke? I just had the problem again (laggy viewer, 30% CPU, for a couple minutes) while the developer tools window was open. Here is the .log (I pressed ctrl-s a couple times out of frustration :grinning:). It got stuck on the first GDRIVE Get file meta-data (success) line and that is when I hit ctrl-s again. After waiting a bit longer it went through and had GDRIVE Upload file (success)

pp-metapdf.js:30041 NO user info -- NOT logging!
chrome-extension://bomfdkbfpdhijjbeoicnfhjbdhncfhig/undefined Failed to load resource: net::ERR_FILE_NOT_FOUND
pp-metapdf.js:51921   STARTUP  Resetting annotation collections for new file with id: 91dd216b-e2b0-0d11-9b66-59a781c9aa95
pp-metapdf.js:51921   SYNC  SharedSession sync_status:undefined
pp-metapdf.js:51921   SYNC  SharedSession sync_status:SYNCED
pp-metapdf.js:51921   SYNC  Setting MP.file autoSync:false without user notification
pdf.worker.js?v=__MP_APP_VERSION__:1205 The provided value 'moz-chunked-arraybuffer' is not a valid enum value of type XMLHttpRequestResponseType.
(anonymous) @ pdf.worker.js?v=__MP_APP_VERSION__:1205
pp-metapdf.js:51921   FIREBASE  Firebase authentication succeeded
pp-metapdf.js:51921   FIREBASE  Registering a new user with sessionID: 16e836cb-83e7-0f0b-bc83-02b1896cf725
pp-metapdf.js:51921   FIREBASE  Added collaborator: (16e836cb-83e7-0f0b-bc83-02b1896cf725)
chrome-extension://bomfdkbfpdhijjbeoicnfhjbdhncfhig/metapdf/pdf.worker.js?v=__MP_APP_VERSION__:1205 The provided value 'moz-chunked-arraybuffer' is not a valid enum value of type XMLHttpRequestResponseType.
(anonymous) @ chrome-extension://bomfdkbfpdhijjbeoicnfhjbdhncfhig/metapdf/pdf.worker.js?v=__MP_APP_VERSION__:1205
pp-metapdf.js:51921   STARTUP  PDF metadata: c89c837af18dfd40b4b46334f8e77b11 [1.2 Acrobat 3.0 Import Plug-in / Acrobat 3.0 Capture Plug-in] (PDF.js: 1.4.323)
pp-metapdf.js:51921   HISTORY  Model added by this user:e543829d-713a-00f4-a228-0380d0935bd1
pp-metapdf.js:12697 Heard one-off message 545 Object {id: "bomfdkbfpdhijjbeoicnfhjbdhncfhig"}
pp-metapdf.js:12697 Heard one-off message 545 Object {id: "bomfdkbfpdhijjbeoicnfhjbdhncfhig"}
pp-metapdf.js:51921   SYNC  Starting sync.
pp-metapdf.js:51921   SYNC  Attempting both cloud and local sync.
pp-metapdf.js:51921   GDRIVE  Get file meta-data (success).
pp-metapdf.js:51921   SYNC  Starting sync.
pp-metapdf.js:51921   SYNC  Attempting both cloud and local sync.
pp-metapdf.js:51921   GDRIVE  Get file meta-data (success).
pp-metapdf.js:12697 Heard one-off message 545 Object {id: "bomfdkbfpdhijjbeoicnfhjbdhncfhig"}
pp-metapdf.js:51921   GDRIVE  Upload file (success).
pp-metapdf.js:14352 Truncating file is finished, calling actual write
pp-metapdf.js:14355 Actual writing finished
pp-metapdf.js:51921   SYNC  Sync done.
pp-metapdf.js:12697 Heard one-off message 545 Object {id: "bomfdkbfpdhijjbeoicnfhjbdhncfhig"}

Again this morning viewer is hanging. Moving the mouse off the page seems to help. For example, I searched for a term in the .pdf the “processing” circle animation stayed on for 10 seconds or so, when I moved the mouse up to hover over the address bar or tabs the search then completes. See a recording here


I’ve been having similar issues. Anecdotally, it seems to occur pretty frequently with PLoS One papers for me, but certainly not exclusively.


Today the problem is gone. We’ll see if it stays that way.


Thanks for helping us debug this issue. It might be an intermittent issue with Google Drive. We plan to push an update of MetaPDF in 2-3 weeks that should address these issues.


The problem is back again. Hopefully that update is close :grinning:


The problem is back again… this is pretty frustrating. I haven’t been able to read papers all afternoon. I am even trying to be patient and get through it anyway… but the performance is HORRIBLE.

Have you been able to push the new PDF viewer yet? I hope ti comes ASAP.


I second @Brett_Israelsen. It is unfortunate.


@Brett_Israelsen are you on Mac?


No, I’m using Windows 10


Genrally the only time I have had trouble with MetaPDF getting stuck is when annotating HUGE PDFs (200+pp, such as conference programs and full-text books).

Reading such documents seems to work fine, as does annotating article length (30pp) or shorter PDFs.


+1 on this, I have been continually having this problem for the past few months. It is terribly frustrating.


+2 on this, I have been continually having this problem for the past few months. It is terribly frustrating.