There is no agreement if the contract is not paid.
In fact, the rule is that a contract in breach is not recognized by FIBA. If NBA goes into lock out the FIBA rule is they do not recognize any NBA contract.
And again, no European basketball club is bound by FIBA rules.
FIBA has not had any jurisdiction over those leagues for years. You are living 11 years in the past. In the present time FIBA has no jurisdiction over European clubs and leagues.
FIBA is no longer in control of European clubs. It hasn't been for years. It's amazing that supposed basketball fans don't even know that European club basketball has nothing at all to do with FIBA and has not for over a decade.