A Layout with many viewports only displays some, or worse, only one viewport content at a time, but clicking inside of of the others activates it but turns on a previously displayed one.
Explore MAXACTVP variable in HELP, it controls how many active viewports you can see at anyone time. Limit is 64 though.
You need to create a large ARRAY and notice that LT hits a limits and stops. You can change this limit by setting the MaxArray system registry variable using SETENV and entering a number between 100 and 10000000. MaxArray must be entered with the capitalization shown.
You create, or try to, a very dense hatch pattern and LT objects that the hatch is too small or the dash length is too short: first make sure that SOLID hatch is not what you really need. If that's not the case, the hatch object limit is set by the MaxHatch environment setting: change this limit by setting the MaxHatch system registry variable using SETENV and entering a number between 100 and 10000000. MaxHatch must be entered with the capitalization shown.
LAYER command is not sorting all your file's layers or blocks alphabetically or any other order you select: explore MAXSORT variable in HELP in LT, inclrease the number displayed until the sorting problem is resolved.