# Installation Fails for Koa.master, Koa.1 and Koa.2 with "KeyError: 'PREVIEW\_LMS\_BASE'"

**URL:** <https://discuss.openedx.org/t/installation-fails-for-koa-master-koa-1-and-koa-2-with-keyerror-preview-lms-base/4257>\
**Category:** Site Operations Help\
**Tags:** koa\
**Created:** [February 11, 2021, 1:54pm UTC](https://discuss.openedx.org/t/installation-fails-for-koa-master-koa-1-and-koa-2-with-keyerror-preview-lms-base/4257 "2021-02-11T13:54:11Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![arbrandes](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.openedx.org/arbrandes/32/158_2.png) [@arbrandes](https://discuss.openedx.org/u/arbrandes)\
**Post date:** [February 11, 2021, 2:10pm UTC](https://discuss.openedx.org/t/installation-fails-for-koa-master-koa-1-and-koa-2-with-keyerror-preview-lms-base/4257/2 "2021-02-11T14:10:50Z")

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Hi @Gaurav_Vijayvergia,

We’ve done some testing around the new [`koa.2a`](https://discuss.openedx.org/t/koa-2a-has-been-tagged/4250) tag yesterday, and none of us ran into this particular issue. Did you follow the [native installation instructions](https://openedx.atlassian.net/wiki/spaces/OpenOPS/pages/1969455764/Koa+Native+Open+edX+platform+Ubuntu+20.04+64+bit+Installation)? If so, did you do anything different? Any settings that are different from the default, perhaps?

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_[View the full topic](https://discuss.openedx.org/t/installation-fails-for-koa-master-koa-1-and-koa-2-with-keyerror-preview-lms-base/4257)._