# Cannot open projects due to "Retry failed: \[Connection.initInstance\]" error after downgrading from v16 to v15 on Windows

**URL:** <https://community.exploratory.io/t/cannot-open-projects-due-to-retry-failed-connection-initinstance-error-after-downgrading-from-v16-to-v15-on-windows/4301>\
**Category:** Issues\
**Created:** [October 30, 2026, 1:38am UTC](https://community.exploratory.io/t/cannot-open-projects-due-to-retry-failed-connection-initinstance-error-after-downgrading-from-v16-to-v15-on-windows/4301 "2026-10-30T01:38:58Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Ikuya\_Murasato](https://community.exploratory.io/user_avatar/community.exploratory.io/ikuya_murasato/32/849_2.png) [@Ikuya\_Murasato](https://community.exploratory.io/u/Ikuya_Murasato)\
**Post date:** [October 30, 2026, 1:38am UTC](https://community.exploratory.io/t/cannot-open-projects-due-to-retry-failed-connection-initinstance-error-after-downgrading-from-v16-to-v15-on-windows/4301/1 "2026-10-30T01:38:58Z")

</div>

After downgrading Exploratory Desktop from v16 to v15.6 on Windows, you may get the following error when opening a project, and the project fails to open.

`Retry failed: [Connection.initInstance], retry:[50/50], interval:[200]`

Also, if you try to reset the R packages, you get the error “Close other projects before initializing the system R packages.” even though no project is open, and the reset does not run.

**Cause**

v16 uses R 4.6, while v15 uses R 4.5. Switching back and forth between the versions seems to leave the R 4.6 environment behind, so the R 4.5 packages are not installed correctly when v15.6 starts.

**Workaround**

You can work around the issue with the steps below.

**Before you start: Check the location of your repository**

First, open “System Settings” on the left side of the project list screen. Then, check the “Repository” item to see which folder is currently used as the repository. By default, it is the `.exploratory` folder directly under your user folder.

 ![image](https://community.exploratory.io/uploads/default/original/2X/b/b7a00d9334af17e829d9bb0734b8ad0537d8ebda.png)

Some setups use a different location, so be sure to check it before you start.

Once you have checked it, quit Exploratory.

1. **Uninstall R 4.6.**  
Uninstall R 4.6 from Windows Settings \> Apps.

2. **Move the R 4.6 packages out of the repository.**  
Open the `R` folder in the repository you checked above. Move the `4.6` folder inside it to a location outside the repository, such as your desktop.

3. **Reinstall Exploratory v15.6.**  
Run the v15.6 installer to reinstall it.

4. **Remove the version information from user\_conf.json.**  
Open `user_conf.json` in the repository you checked above with a text editor. Delete the `"version"` line shown below and save the file.

5. **Start Exploratory and install the R packages.**  
When you start Exploratory, the R package installation screen appears. Start the installation. Once it finishes, you can open your projects again.