Can't rebase stream to the foundation baseline. Probably the baseline is corrupted.
Is it possible to fix this baseline?
cleartool: Error: Version map for baseline is unavailable.
cleartool: Error: Unable to get unlabelled baselines in foundation
cleartool: Error: Unable to determine if configuration is valid
cleartool: Error: Unable to rebase stream
First, are you sure to select the right baseline?
If you select a composite baseline, it is per its nature unlabelled.
Second, what version of ClearCase are you using? Is your project a multisite one?
Your error message is seen in the IBM technote "Creating a child stream in a ClearCase MultiSite environment results in Error"
You can check out this IBM technote "Version map for baseline is unavailable"