Sometimes messages like below can be seen even when the number and size of global variables in the OPSVIEW panel 4.8 are very low or have values that should be handled by the number of blocks reserved by the parameter GLOBALMAX:
OPS/MVS OPS4290O GLOBAL VARIABLE WORKSPACE IS 98.5% FULL (39400 OF 40000 BLOCKS USED). PROGRAM=xxxxxxx
Global variable blocks are also used by RDF tables so even having just a few global variables visible in the OPSVIEW panel 4.8 there can be a large number of blocks being consumed by RDF tables.
Check if you have big unused RDF tables by visiting the panel 2.6. You may have old tables that can be deleted or user tables that may be cleaned up. If the global variables and RDF tables usage are both in normal consumption and nothing can be deleted you may need to increase the value of the parameter GLOBALMAX and recycle OPSMAIN. Be aware that increasing the value of this parameter may require a bigger SYSCHK1 dataset so you may need to allocate a larger SYSCHK1 dataset, copy the contents of the current dataset to the new one using IDCAMS REPRO and start OPS using the new dataset.