Number of data sets in analytical query

hello i had to run queries on analytical service

my data set with 16 buckets. i had uploaded them using local link to datasets but

first i had the that error message when i try to connect data set

Error connecting/disconnecting link. Got status: 500 from server.[{“code”:22001,“msg”:"Connect link failed {“Default.Local.observations” : “Maximum number of active writable datasets (8) exceeded”, “Default.Local.organizations” : “Maximum number of active writable datasets (8) exceeded”, "D…

and it give me empty result does
what does this mean and does there is any restriction on bucket data set number
could any one help me