Hello SergiG0101,
Welcome to the Microsoft Community, I'm glad to have this opportunity to help you with your problem.
I understand that you were unable to load the sidebar in the Loop with the error "Oops! Something went wrong while opening the workspace!".
I'm sorry to hear that you're experiencing this error, it's a real inconvenience to work with.
While we haven't reproduced your issue in our testing, we did receive feedback from users who had the same issue as you with the sidebar failing to load, and this may be a pending bug. As Microsoft Loop is currently in beta, there are some issues with using it. Regarding the issue you are experiencing, this is a pending fix. We are in the process of gathering more information about this and will provide internal feedback to the Loop's development team when we have done so. And we expect them to update and fix it as soon as possible.
While waiting for the fix, please try the following options to see if they work.
1. To work on a PC, try using the Loop client temporarily to see if you encounter the same problem.
On Windows, you can search for and download the Microsoft Loop application from the Microsoft Store.
2. Clear your browser cache (Edge for example).
- In Edge, select Settings and more in the upper right corner of your browser window.
2. Select Settings > Privacy, search, and services.
3. Select Choose what to clearunder Clear browsing data > Clear browsing data now.
4. Under Time range, choose a time range from the list.
5. Select Cookies and other site data, and then select Clear now.
Disclaimer*: Your browser automatically saves temporary internet files to help pages load faster. Clearing this cache will sometimes fix website issues. Please back up all your personal files first, such as Favorites, to ensure you do not lose data.*
You can also provide feedback through official channels, more feedback will increase the development team's attention to this issue, and therefore it may be resolved faster.
How to give feedback: In Loop web site, click on Setting and More Options in the upper right corner (three dots) and then select Help and Feedback -> Provide Feedback.
If the above methods do not work, unfortunately, we do not have more effective solutions for the time being, so please be patient and wait for the fix.
Again, we apologize for the inconvenience caused and thank you for your understanding and feedback.
Best wishes
Ian - MSFT | Microsoft Community Support Specialist