ArcGIS Enterprise 11.5 Upgrade Errors

[FeelingMappy]

Hi All!

Upgrade from 10.9.1 to 11.5 results in inaccessible Portal, returning the error.html page with an infinent loop.

We have tested upgrading from 10.9.1 to 11.1 first, as well as upgrading to 11.3. All these upgrades work, except for 11.5.

Portaladmin page is still accessible but attempting to access /portal/home/index.html results in the error  /portal/home/error.html

Any back is welcomed.

[CodyPatterson]

Hey @FeelingMappy 

In terms of skipping intermediate versions, it appears that in most cases it's perfectly fine to do so, 11.3 to 11.3 and then 11.3 to 11.5 for an example, but in this case, if you're having issues going from 11.3 to 11.5, would it be possible to try an intermediate 11.4 version then to 11.5 to see if that works? Along with that, are any log files generated that could tell why the error may be happening or any console errors?

Cody

[TimoT]

Hi @FeelingMappy,

I've run into the same error before, with 11.5 upgrades being anecdotally the worst offender across all 11.X upgrades so far. In all cases, the issue was due to browser cache, which is mentioned in the Portal upgrade documentation

Have you tried clearing browser cache, incognito mode, and/or a different browser? Also ensure you are using a supported browser.

[A_Wyn_Jones]

Check your index status in Portal admin.

https://developers.arcgis.com/rest/enterprise-administration/portal/reindex/

Rebuild the index if required.

As mentioned, there is the need to clear browser caches especially with the following patch if it's installed:
https://support.esri.com/en-us/patches-updates/2025/portal-for-arcgis-11-5-web-applications-patch