# Error launching application after upgrade **URL:** \ **Category:** Ignition\ **Tags:** ignition81\ **Created:** [October 12, 2023, 6:28am UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376 "2023-10-12T06:28:06Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![Sijil\_V](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@Sijil\_V](https://forum.inductiveautomation.com/u/Sijil_V)\ **Post date:** [October 12, 2023, 6:28am UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376/1 "2023-10-12T06:28:06Z")
Hello, Tried to upgrade Ignition version from 8.1.18 to 8.1.26. After upgrade I tried to open the designer and got error like this ![image](https://us1.discourse-cdn.com/inductiveautomation/original/3X/4/d/4d44072d613691f4309c14ed477a97cfe9704e2b.png) Has anyone encountered an issue like this? How to solve this ---
**Author:** ![bschroeder](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/bschroeder/32/13260_2.png) [@bschroeder](https://forum.inductiveautomation.com/u/bschroeder)\ **Post date:** [October 12, 2023, 7:41am UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376/2 "2023-10-12T07:41:41Z")
Navigate to your users diectory, :\Users\svenugopal. Make a backup of the .ignition folder. Then delete the .ignition folder. Re-Open designer launcher and re-open the project. ---
**Author:** ![Sijil\_V](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@Sijil\_V](https://forum.inductiveautomation.com/u/Sijil_V)\ **Post date:** [October 12, 2023, 8:35am UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376/3 "2023-10-12T08:35:28Z")
Hello bschroeder, Thanks for your help. Still it is showing this error. I am attaching the launch error log Launch failed on step "DownloadPyLibStep" with error: java.lang.Exception: Unable to save pylib to C:\Users\svenugopal.ignition\cache\resources\pylib\58521b6a210a505966119c393901959b.zip at com.inductiveautomation.ignition.client.launch.steps.DownloadPyLibStep.downloadPyLib(DownloadPyLibStep.java:217) at com.inductiveautomation.ignition.client.launch.steps.DownloadPyLibStep$DownloadPyLibZip.maybeDownload(DownloadPyLibStep.java:148) at com.inductiveautomation.ignition.client.launch.steps.DownloadPyLibStep$DownloadPyLibZip.run(DownloadPyLibStep.java:87) at com.inductiveautomation.ignition.client.launch.steps.DownloadPyLibStep$DownloadPyLibZip.run(DownloadPyLibStep.java:74) at com.inductiveautomation.ignition.client.launch.steps.AbstractLaunchStep.runLockedAction(AbstractLaunchStep.java:95) at com.inductiveautomation.ignition.client.launch.steps.BaseStep.runLockedAction(BaseStep.java:21) at com.inductiveautomation.ignition.client.launch.steps.DownloadPyLibStep.run(DownloadPyLibStep.java:64) at com.inductiveautomation.ignition.client.launch.AbstractStepRunner.run(AbstractStepRunner.java:33) at java.base/java.lang.Thread.run(Thread.java:829) ---
**Author:** ![bschroeder](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/bschroeder/32/13260_2.png) [@bschroeder](https://forum.inductiveautomation.com/u/bschroeder)\ **Post date:** [October 12, 2023, 9:09am UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376/4 "2023-10-12T09:09:07Z")
Is this when you are trying to upgrade designer or when you are trying to start a project from in designer? My main trick is what I wrote for these type of issues. Usually deleting the folder is the trick. Were you able to backup and DELETE the .ignition folder successfully? If not that may point to a permissions issue. ---
**Author:** ![Sijil\_V](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@Sijil\_V](https://forum.inductiveautomation.com/u/Sijil_V)\ **Post date:** [October 12, 2023, 10:19am UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376/5 "2023-10-12T10:19:27Z")
Infact I was trying to upgrade from Version 8.1.18 to 8.1.26. Installation was successful. But after that when I tried to open the designer, it asked whether I need to upgrade to 1.1.26. I accepted that and it started installing the same. After installation during startup it was showing "downloading project" and this popup comes up. I did the backup and deleted the folder. ---
**Author:** ![bschroeder](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/bschroeder/32/13260_2.png) [@bschroeder](https://forum.inductiveautomation.com/u/bschroeder)\ **Post date:** [October 12, 2023, 10:25am UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376/6 "2023-10-12T10:25:01Z")
Unfortunately I'm out of ideas on this. Hopefully someone will chime in that has another idea or you may need to engage with support. ---
**Author:** ![Sijil\_V](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@Sijil\_V](https://forum.inductiveautomation.com/u/Sijil_V)\ **Post date:** [October 12, 2023, 10:26am UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376/7 "2023-10-12T10:26:53Z")
Anyways thanks for your support ---
**Author:** ![Sijil\_V](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@Sijil\_V](https://forum.inductiveautomation.com/u/Sijil_V)\ **Post date:** [October 12, 2023, 2:03pm UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376/8 "2023-10-12T14:03:13Z")
So I would like to give an update on this. The issue was with my Antivirus. It was preventing from downloading the python lib when launching designer. It would be better if we disable the antivirus or allow this particular installation. Problem is solved ---
**Author:** ![bschroeder](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/bschroeder/32/13260_2.png) [@bschroeder](https://forum.inductiveautomation.com/u/bschroeder)\ **Post date:** [October 12, 2023, 2:03pm UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376/9 "2023-10-12T14:03:55Z")
Awesome. What AntiVirus do you have? Just for my own personal knowledge. ---
**Author:** ![Sijil\_V](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@Sijil\_V](https://forum.inductiveautomation.com/u/Sijil_V)\ **Post date:** [October 12, 2023, 2:07pm UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376/10 "2023-10-12T14:07:47Z")
Trellix Endpoint Security ---
**Author:** ![Kevin.Herron](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/kevin.herron/32/7259_2.png) [@Kevin.Herron](https://forum.inductiveautomation.com/u/Kevin.Herron)\ **Post date:** [March 7, 2024, 8:52pm UTC](https://forum.inductiveautomation.com/t/error-launching-application-after-upgrade/80376/11 "2024-03-07T20:52:12Z")
Split this topic on March 7, 2024, 8:52pm UTC A post was split to a new topic: [Checksum Mismatch Opening Designer](https://forum.inductiveautomation.com/t/checksum-mismatch-opening-designer/86992)