Thank you for your post.
We are investigating a reason for the issue, and looks like this is related to the failed pull process for the folder metadata that you were faced with.
You can check if the issue would be reproduced after you would apply the mentioned workarounds for the pull from Salesforce.
If the workarounds won't help, as an additional workaround to avoid the error during building your changes, please follow the next steps:
1. open the Project menu and disable the project structure sync option;
2. after this, please open the Static Resource Bundle Explorer (from the menu View), find the 'TWS_Sync_Data' file and delete it - the file will be deleted on your org also;
3. then please open the Project menu again and enable the project structure sync functionality again - after this, the filed will be created repeatedly and it would have a proper format.
Please let me know if this would help to solve the issue or if you have any additional questions.