use isdefined

Author: kanav99

src/callbacks.jl

@@ -765,7 +765,7 @@ end
 
 function apply_callback!(integrator,callback::Union{ContinuousCallback,VectorContinuousCallback},cb_time,prev_sign,event_idx)
 
-  if is_integrator_adaptive(integrator)
+  if isadaptive(integrator)
     set_proposed_dt!(integrator, max(nextfloat(integrator.opts.dtmin), callback.dtrelax * integrator.dt))
   end
 

src/integrator_interface.jl

@@ -580,4 +580,5 @@ has_destats(i::DEIntegrator) = false
 
 Checks if the integrator is adaptive
 """
-is_integrator_adaptive(integrator::DEIntegrator) = integrator.opts.adaptive
+isadaptive(integrator::DEIntegrator) =
+        isdefined(integrator.opts, :adaptive) ? integrator.opts.adaptive : false