Overall third party services

APPLIES TO: DIY Nightscout

For Nightscout as a service contact directly support at t1pal.com or use the Get Support links.

Before troubleshooting

Check the services you're using.

Dexcom: https://status.dexcom.com/

Carelink US: https://carelink.minimed.com/

Carelink non-US: https://carelink.minimed.eu/app/login

GitHub: https://www.githubstatus.com/

Heroku: https://status.heroku.com/

Atlas: https://status.cloud.mongodb.com/

GitHub and Heroku

A valid GitHub Directory could not be found.

When trying to deploy a new Nightscout site, this message appears when clicking Deploy to Heroku.

  • Change browser and retry.

Cannot find cgm-remote-monitor in Heroku / No GitHub source visible

When updating Nightscout, cgm-remote-monitor doesn't appear automatically in Heroku under your repository name.

When updating Nightscout, your repository name doesn't appear in Manual Deploy so that you can't select the master branch.

  • Disconnect and re-Connect like this:

  • If it doesn't help try to re-authorize as explained below:

Cannot find cgm-remote-monitor in Heroku: Item cannot be retrieved

When updating Nightscout, cgm-remote-monitor doesn't appear automatically in Heroku under your repository name and an error message appears when you try to connect to GitHub.

  • In Heroku, go to Account Settings

  • Select Applications and click Re-authorize

  • Click Authorize GitHub in the pop-up.
  • If it doesn't help, you can also try to Revoke access... before going back to Re-Connect your GitHub account. This is necessary if someone else did setup Nightscout for you and left his own GitHub connected to your Heroku account.


Limit of one free cluster.

When creating a new site or migrating (usually not the first attempt), when reaching Target Cluster.

  • Click the leaf top left in your Atlas account. Look at the Project Name you wanted to use when creating your new cluster, it shouldn't contain a cluster yet (like the example below, I tried to create a new Nightscout site but there is already a cluster inside the project I wanted to use). You can't have two clusters in a free project. Click your Project Name.
  • This should not happen in normal conditions. Before deleting a cluster, check it doesn't contain your data!

  • Click on Collections in the cluster you selected.

  • Click on entries

  • In the case there is data, like in the example below, don't use this cluster. Leave it like this and create a new one.

  • If there no data, you can safely delete it.

  • In this cluster you want to delete click ... then Terminate

  • Copy the cluster name to confirm then click Terminate

  • Wait until the operation completes.
  • You can now use this project name to create a new site.

Nightscout page doesn't open

Application Error

Update Nightscout to latest release. It might not fix your issue but it will help find a solution.

  • If you didn't migrate your Heroku database from mLab to Atlas create a new Atlas database.
  • If you didn't migrate from Azure to Heroku create a new site create a new Nightscout site with Heroku.
  • If you're creating a new Nightscout site, it might have failed because of a wrong connection string. Delete your Heroku app and deploy again after checking the Atlas connection string is correct.
  • If your site is already up to date:

Restart all dynos

  • Log in Heroku, go to Settings, More, Restart all dynos.

Nightscout stopped working after a few weeks

Same screen than above but you received a mail from Heroku telling you you're out of dyno hours...

  • Check your remaining dyno hours in Heroku, click on your profile picture top right and select Account Settings, then Billing.

  • An account without credit card information has 550 free dyno hours, with credit card information 1000.

Boot Error - Unable to connect to Mongo

Look at this dedicated page.

No data in Nightscout

New Nightscout sites Check you database is not read only.

Make sure your Nightscout time zone is correct.

Dexcom data not showing

Dexcom Share

Make sure you have Dexcom Share turned ON in your Dexcom app. In the Dexcom app's main screen, find the triangle made of dots. If the dots are grey, you do not have Share turned on. Tap the triangle, and follow the directions to add a follower (yourself if you don't have someone else you'd like to invite) and turn on Share.

If you are using a Dexcom system, and your data is not appearing in Nightscout, there are only a limited number of reasons for that. You should check your (1) Heroku settings and (2) Dexcom Share.

NOTE: The #1 reason why BGs aren't showing is that you have mismatched password and user names in Heroku settings and Dexcom.

Heroku Settings

Login to your Heroku account and from within Heroku Settings, click on the Reveal Config Vars

Now from the Config Vars area, check the following (see screenshot below for reference):

  1. You must use the same BRIDGE_PASSWORD or BRIDGE_USER_NAME that your Dexcom mobile app is using.
  2. You must have bridge and careportal on the ENABLE line (you can have other values there...but don't forget these two).
  3. If you are outside the USA, you must add BRIDGE_SERVER set to EU in Heroku settings.
  4. Your careportal must be one word in the ENABLE line, sometimes autocorrect makes it two words.
  5. If using mmol, make sure you have spelled that value correctly in the DISPLAY_UNITS.

One thing that can happen if you have an incorrect Dexcom login/password in your Share account settings and/or in your Nightscout BRIDGE settings is that Dexcom will lock your account...and you won't see CGM data in Nightscout. If you notice your CGM readings disappeared, but everything else is flowing...check your Heroku logs that are viewable by selecting "View Logs" from the drop-down menu underneath the "More" option.

Do your logs have "SSO authentication errors" like in the red box highlighted above? If you do, then:

  1. Delete your BRIDGE entries within Heroku settings. Don't delete the variables, just delete the values of BRIDGE_PASSWORD and BRIDGE_USER_NAME.
  2. Wait 15 minutes and then follow the directions below. It is important to wait 15 minutes: the reason you can't log in right now is that your Dexcom account has a temporary lock from the passwords in the step above being incorrect. The temporary lock will expire after 10-15 minutes of giving the account login a break from the incorrect logins. So, definitely wait or else you'll just keep prolonging the issue.

When you change these variables, Heroku restarts Nightscout. So now everything should work.

About your Bridge password and user name

The BRIDGE_PASSWORD and BRIDGE_USER_NAME are NOT visible from within your Dexcom mobile app or online account. The values of them are what you entered into your Dexcom mobile app when you VERY FIRST logged into that app however long ago. If you have double-checked everything else that could be incorrect and BGs still aren't showing in Nightscout, then you likely have those Bridge values incorrect. To fix that, delete your Dexcom app (don't stop the session before deleting the app...just keep it going). Download the app again from the iPhone's App Store and login to the freshly-downloaded Dexcom app. Take note that deleting the app will not stop your session, your session will pick right back up once the transmitter pairs again. The BRIDGE_USER_NAME is not an email address. Use that exact same login now in your Heroku settings. You can leave your Loop's Share account info blank...you just need the transmitter ID going forward.

Dexcom username issue

It seems that Dexcom share somewhere in its systems is not capable of using the username other than ordinary letters.

By changing the username, this has been solved for everyone who has tried so far. If that doesn't work for you, please report it at https://github.com/nightscout/cgm-remote-monitor/issues/5608 or if you can comment on any Facebook post that linked to this site.

Change username

Unfortunately, it is not possible to change the username of a Dexcom account. You have to create a whole new account.

Create new account

You can only associate one email address with a Dexcom account, so it might be a good idea to create a new email address and associate it to your current account so that you can use your current email with the new account. Go to https://www.dexcom.com and look for where to create accounts. Follow the instructions to create a new account. The alternative is to delete the old account. But do not do that. It may be good to be able to go back and retrieve historical data. Make sure the new username contains only letters. It is better to stick to a-z. We know that the period . underscore _ and at @ characters creates problems, but we do not know which other characters can create problems.

Reinstall Dexcom Transmitter app

When you install the Dexcom app, it is linked to a Dexcom account. Unfortunately, there is no way to switch accounts. What you have to do is simply uninstall the app and reinstall it. In principle, it is the same procedure as changing phone. Of course, this time you should log in with the new account.

  • Write down the current Transmitter ID. You can find the ID if you look in settings in the Dexcom app.
  • Uninstall the Dexcom app
  • Reinstall the Dexcom app
  • Log in with your new account
  • Follow the instructions in the app.
  • For G6 do not select sensor code. The sensor code is already saved on your old transmitter.
  • Enter the transmitter ID and wait for pairing
  • Answer yes to the question "have you inserted sensor"

You then have to re-invite your followers.


Check your Heroku settings match your new credentials (see above)


CareLink with mmconnect data source stopped functioning for most . Remove the mmconnect plugin from ENABLE if you use Heroku.

First verify you can see your BG in Clarity.

If data is present open Heroku and check you app didn't fall asleep.

A sleeping app might be due to your Heroku free plan: a Hobby plan makes the app never sleep. https://www.heroku.com/pricing

Another reason for a sleeping app can be due to a failure to obtain data from Dexcom Share, check the logs to understand the reasons.

UpTime Robot

Using an uptime robot with a bad password, or other issues originating from Nightscout can lead to a locked account (Dexcom) or Heroku addresses ban. This is not a recommended solution as it might generate a global Heroku IP blacklist lock that could propagate to all other users. If you use Nightscout, uploading data in the cloud or even just having a browser or an app downloading data should be enough to keep your app awake.

Error code instead of a BG value

Nightscout implements Dexcom error codes as listed below:

Code Corresponding error
?SN Sensor not active
?MD Minimal deviation
?NA No antenna
?NC Sensor not calibrated
?CD Counts deviation
?AD Absolute deviation
??? Power deviation
?RF Bad RF

Data timing issues

Basal is shifted in time

  • Check the time zone is correct for your currently active profile in your Nightscout Profile editor.

Data in the future

  • Check you don't have data in the future with the Admin tools. Remove them if existing.

  • If this isn't working, or shows no future data, check in Atlas
  • Open your Nightscout cluster and select Collections

  • In Entries type {date:-1} and click Find

  • Delete the entries in the future (manually) with the bin icon

Database full

Free databases like M0 Sandbox provided by Atlas will only hold a limited amount of data (512MB) and you will eventually need to manually cleanup. You can extend the capacity to 2 and 5GB paying an M2 or M5 Shared cluster.

  • Make sure your Nightscout site has Database Size enabled to monitor database capacity. Look here for more information on this plugin.

  • Check in Atlas
  • Open your Nightscout cluster and select Collections

  • Click your database name (hidden left). Check theDATABASE SIZE is indeed close to or at the limit then look at these three collections Documents size: devicestatus, entries and treatments.

  • Open Nightscout Admin tools.
  • Depending on the collection you identified above, choose which of the following you want to cleanup:

You can cleanup (enter the number of days to keep) or delete your devices status:

Same for Treatments:

And Glucose entries. If you are reluctant to lose historical data you should consider opting for a paid database solution.

Reports slow loading or timeout

Loopers might experience Nightscout taking an extremely long time or even timing out when creating reports due to the profiles collection database growing too big.

Two solutions are available:

  1. Follow this video (set it full screen in 720p) to selectively delete profiles https://www.youtube.com/watch?v=iipp0MfPKNQ
  2. Delete all profiles in Atlas

Log in to Atlas https://account.mongodb.com/account/login

Select your cluster then COLLECTIONS

Select the profile collection and click the bin icon to delete all profiles.

Write profile in the box then click Drop

Open your Nightscout and create a new profile (mind the time zone!), authenticate and save it.

If you are using Loop, temporarily change a basal rate in Loop, and confirm your profiles now show up in Nightscout.