# Migrating from Radzen.Blazor 2.x to 3.x **URL:** \ **Category:** Radzen.Blazor Components\ **Created:** [January 19, 2021, 9:16am UTC](https://forum.radzen.com/t/migrating-from-radzen-blazor-2-x-to-3-x/6353 "2021-01-19T09:16:58Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![rsb-abby](https://forum.radzen.com/user_avatar/forum.radzen.com/rsb-abby/32/5866_2.png) [@rsb-abby](https://forum.radzen.com/u/rsb-abby)\ **Post date:** [January 31, 2021, 8:43pm UTC](https://forum.radzen.com/t/migrating-from-radzen-blazor-2-x-to-3-x/6353/21 "2021-01-31T20:43:44Z")
Hi there. Has just started working with Radzen components in VS 2019 but after the migration to 3.x the CSS styling is lost. The changes recommended for the CSS, where do i apply them? I had not added any custom styling. - `.ui-` is now `.rz-` - `.pi` is now `.rzi` also `.pi-` is `.rzi-` etc... How can I located the CSS? RS ---
**Author:** ![korchev](https://forum.radzen.com/user_avatar/forum.radzen.com/korchev/32/4_2.png) [@korchev](https://forum.radzen.com/u/korchev)\ **Post date:** [February 1, 2021, 6:16am UTC](https://forum.radzen.com/t/migrating-from-radzen-blazor-2-x-to-3-x/6353/22 "2021-02-01T06:16:05Z")
If you haven't used any custom styling you just need to include the theme CSS as always (listed in the getting started instructions). Also make sure to clear your browser cache. ---
**Author:** ![rsb-abby](https://forum.radzen.com/user_avatar/forum.radzen.com/rsb-abby/32/5866_2.png) [@rsb-abby](https://forum.radzen.com/u/rsb-abby)\ **Post date:** [February 1, 2021, 8:13am UTC](https://forum.radzen.com/t/migrating-from-radzen-blazor-2-x-to-3-x/6353/23 "2021-02-01T08:13:33Z")
Korchev, Thank you for your reply i had it all running until i upgraded. When i downgrade to 2.9 or lower the styles all work. i have added the following code... ![image](https://forum.radzen.com/uploads/default/original/2X/e/e4e5686e74f8f41e62abb2860e30ad7564e93519.png) seems the file cannot be found. There is a squiggly line under the following code. Thanks RB ---
**Author:** ![korchev](https://forum.radzen.com/user_avatar/forum.radzen.com/korchev/32/4_2.png) [@korchev](https://forum.radzen.com/u/korchev)\ **Post date:** [February 1, 2021, 8:51am UTC](https://forum.radzen.com/t/migrating-from-radzen-blazor-2-x-to-3-x/6353/24 "2021-02-01T08:51:54Z")
You are still using older files. Check your browser caching. Also the squiggly line appears for the blazor.webassembly.js file - this means the problem isn't related to Radzen. I am closing this thread now as I believe all known issues have been addressed. To sum it up: 1. If you have applied any customizations check my first post to apply the changes manually to your customizations. 2. If you are using a custom Radzen theme - go to the application settings in Radzen and save them. This will update your custom theme. 3. If you experience problems after upgrade - clear your browser cache and or try incognito mode. Browsers sometimes cache the CSS file too aggressively and continue serving the old copy. ---
**Author:** ![korchev](https://forum.radzen.com/user_avatar/forum.radzen.com/korchev/32/4_2.png) [@korchev](https://forum.radzen.com/u/korchev)\ **Post date:** [February 1, 2021, 8:51am UTC](https://forum.radzen.com/t/migrating-from-radzen-blazor-2-x-to-3-x/6353/25 "2021-02-01T08:51:56Z")
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**Author:** ![korchev](https://forum.radzen.com/user_avatar/forum.radzen.com/korchev/32/4_2.png) [@korchev](https://forum.radzen.com/u/korchev)\ **Post date:** [February 1, 2021, 8:52am UTC](https://forum.radzen.com/t/migrating-from-radzen-blazor-2-x-to-3-x/6353/26 "2021-02-01T08:52:17Z")
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