# GUI Errors after new installation **URL:** \ **Category:** Software\ **Created:** [August 17, 2021, 3:17am UTC](https://www.evolver.bio/t/gui-errors-after-new-installation/317 "2021-08-17T03:17:02Z")\ **Posts on this page:** 1\ **Showing post:** 9
**Author:** ![bgwong](https://yyz1.discourse-cdn.com/flex035/user_avatar/www.evolver.bio/bgwong/32/262_2.png) [@bgwong](https://www.evolver.bio/u/bgwong)\ **Post date:** [September 20, 2021, 11:51pm UTC](https://www.evolver.bio/t/gui-errors-after-new-installation/317/9 "2021-09-20T23:51:30Z")
I think there are two issues here: 1. I think if you manually update the server, you might have to manually set the “active” calibration file. Otherwise, it will probably error out. You can find it on the [calibrations.json example](https://github.com/FYNCH-BIO/evolver/blob/master/evolver/calibrations.json) from the previous posts. Make sure it has a valid `"active": true` entry on the json that you want to be active. 2. Seems like data isn’t properly getting to the Pi from one of the Arduinos (OD135) To properly communicate with the OD135 photodiode, seems like a longer delay would help. Here is instructions on how to do this. [Pumps not working in chemostat mode - #5 by heinsz](https://www.evolver.bio/t/pumps-not-working-in-chemostat-mode/266/5) Zack can correct me if I’m wrong! Good luck! --- _[View the full topic](https://www.evolver.bio/t/gui-errors-after-new-installation/317)._