1. Unlock
When selected, checked-out files, right click and select TortoiseSVN, choose clean up clean up, as shown below interface
2. Update
Right-click checkout files -> SVN Update
If the result of the error is still there, you can try many times! ! !
I tried the n-th time, success! ! !
Reference links:
https://blog.csdn.net/weixin_38168620/article/details/82179948