# P21 community application Update notification

**URL:** <https://forum.certara.com/t/p21-community-application-update-notification/4424>\
**Category:** Troubleshooting and Problems\
**Created:** [September 8, 2026, 8:06pm UTC](https://forum.certara.com/t/p21-community-application-update-notification/4424 "2026-09-08T20:06:41Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Swatilekha\_Banerjee](https://avatars.discourse-cdn.com/v4/letter/s/76d3ee/32.png) [@Swatilekha\_Banerjee](https://forum.certara.com/u/Swatilekha_Banerjee)\
**Post date:** [September 8, 2026, 8:06pm UTC](https://forum.certara.com/t/p21-community-application-update-notification/4424/1 "2026-09-08T20:06:41Z")

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Users are getting errors while auto update of Pinnacle 21 community. Please Advise.

 ![f9096f_image](https://us1.discourse-cdn.com/certara/original/2X/d/decfbd6f3656db2dea24fe5618bfc029f56305d7.png)

 ![image](https://us1.discourse-cdn.com/certara/original/2X/6/6776dd5f05718828691abd4a2b6031c27146d678.png)

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**Author:** ![Trevor\_Mankus](https://sea1.discourse-cdn.com/certara/user_avatar/forum.certara.com/trevor_mankus/32/2650_2.png) [@Trevor\_Mankus](https://forum.certara.com/u/Trevor_Mankus)\
**Post date:** [September 9, 2026, 4:35pm UTC](https://forum.certara.com/t/p21-community-application-update-notification/4424/2 "2026-09-09T16:35:51Z")

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First for foremost, welcome to the Community forum @Swatilekha_Banerjee !!

Auto update is failing because you are trying to upgrade from P21C 4.1.0 to P21C 4.2.0. We recently rolled out the 4.2.0 release, and you can read more about the upgrade process here: [Pinnacle 21 Community 4.2.0 is here, and this one requires a manual install](https://forum.certara.com/t/pinnacle-21-community-4-2-0-is-here-and-this-one-requires-a-manual-install/4422)

In short: Starting with v4.2.0, Community is code-signed as **Certara** rather than **Pinnacle 21**. Your currently installed version checks that an update is signed by the same publisher it was originally installed under, so it will reject the 4.2.0 package rather than install it. Nothing is broken. The signature simply doesn’t match what your existing install expects. This is a one-time interruption. Once you’re on 4.2.0, auto-update resumes as normal and future releases will install themselves the way you’re used to.

You will want to uninstall P21C from your computer, then download the 4.2.0 installer from our Downloads page, and install from scratch (this time only).

I hope this helps!

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**Author:** ![Swatilekha\_Banerjee](https://avatars.discourse-cdn.com/v4/letter/s/76d3ee/32.png) [@Swatilekha\_Banerjee](https://forum.certara.com/u/Swatilekha_Banerjee)\
**Post date:** [September 14, 2026, 6:51pm UTC](https://forum.certara.com/t/p21-community-application-update-notification/4424/3 "2026-09-14T18:51:52Z")

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Thanks @Trevor_Mankus . This is really helpful.