Error with Bootstrap

I am trying to get the bootstrap for a fitted pumas model ( the minimization was successful and the infer function ran successfully as well). The model is as follows:

pac_carb_ANC  = @model begin
  @param begin

    tvPOP_CIRC0      ∈ RealDomain(lower=0.00)
    tvPOP_MTT    ∈ RealDomain(lower=0.00)
    tvPOP_GAMMA    ∈ RealDomain(lower=0.00)
    tvPOP_SLOP    ∈ RealDomain(lower=0.00)
    tvPOP_SLOPC    ∈ RealDomain(lower=0.000)
    Ω_1        ∈ PDiagDomain(3)
    Ω_2        ∈ PDiagDomain(1)
    σ_prop    ∈ RealDomain(lower=0.00)
  end

  @random begin
    η_1 ~ MvNormal(Ω_1)
    η_2 ~ MvNormal(Ω_2)
  end

  @covariates BSA SEX BILIRUBIN AGE Regimen   # BSA (/m2) , SEX 0 Female 1 male  Bilirubin (micromole),  AGE (years)


  @pre begin
  Vc = 12.8
  Vp = 252 * (BSA/1.8)^1.17
  VMEL = 37.4 * 1.2^SEX * (BSA/1.8)^0.842 * (BILIRUBIN/7)^(-0.167) * (AGE/56)^(-0.352)
  KMEL = 0.53
  VMTR = 169 * 1.2^SEX * (BSA/1.8)^0.911
  KMTR = 0.83 * 2.11^SEX
  K21 = 1.15 * 0.893^SEX
  Q = 20.1 * (BSA/1.8)^0.724
  cl = 7.38
  q = 90.5
  vc = 11.9
  vp = 8.23
  CIRC0  = tvPOP_CIRC0 * exp(η_1[1])
  MTT    = tvPOP_MTT * exp(η_1[2])
  SLOP  = tvPOP_SLOP * exp(η_1[3])
  SLOPC  = tvPOP_SLOPC * exp(η_2[1])
  GAMMA = tvPOP_GAMMA
  NN = 3
  KTR = ((NN+1)/MTT)
  end

  @init begin
    Prol  = CIRC0
    Transit1 = CIRC0
    Transit2 = CIRC0
    Transit3 = CIRC0
    Circ = CIRC0
  end
  @vars begin

    CONC = (Central/Vc)
    conc = (central_carb/vc)
    EDRUG = (1-(SLOP*CONC))
    EDRUGC = (1-(SLOPC*conc))
    FEED = (abs(CIRC0/Circ)^GAMMA)

  end
  @dynamics begin

    Central' =  -((CONC*VMEL)/(CONC + KMEL)) + (K21*PERIPH1) -  ((CONC*VMTR)/(CONC + KMTR)) + ((Q/Vp)*PERIPH2) - ((Q/Vc)*Central)
    PERIPH1' = -(K21*PERIPH1) +  ((CONC*VMTR)/(CONC + KMTR))
    PERIPH2' = - ((Q/Vp)*PERIPH2) + ((Q/Vc)*Central)
    #CARB' = -KC*CARB
    central_carb' = -(cl/vc)*central_carb + (q/vp)*Periph_carb - (q/vc)*central_carb
    Periph_carb' = (q/vc)*central_carb - (q/vp)*Periph_carb
    # PD
    Prol'    = ((((KTR*Prol)*EDRUG*FEED*EDRUGC))-(KTR*Prol))
    Transit1' = ((KTR*Prol)-(KTR*Transit1))
    Transit2' = ((KTR*Transit1)-(KTR*Transit2))
    Transit3' = ((KTR*Transit2)-(KTR*Transit3))
    Circ' = ((KTR*Transit3)-(KTR*Circ))
  end

  @derived begin
    CONC  = @. (Central/Vc)
    conc = (central_carb/vc)
    E = @. Circ
    ANC = @. Normal(E, E*σ_prop)
  end
end

However the bootstrap runs for very long time and it keeps giving the following error:

bs= infer(fit_pacli_carb_ANC, Pumas.Bootstrap(rng=MersenneTwister(1234),
           samples=200, ensemblealg = EnsembleThreads()))
┌ Warning: Interrupted. Larger maxiters is needed.
└ @ SciMLBase /builds/PumasAI/PumasSystemImages-jl/.julia/packages/SciMLBase/mndcy/src/integrator_interface.jl:331
^C
┌ Warning: Interrupted. Larger maxiters is needed.
└ @ SciMLBase /builds/PumasAI/PumasSystemImages-jl/.julia/packages/SciMLBase/mndcy/src/integrator_interface.jl:331
^C

Could you please let me know what does this warning message mean and if there is a way to make it run faster ?

Thanks

It looks like some of the resampled datasets have issues. Do you get these warnings during the fitting of the original model

Actually the fitting of the original model runs very smooth with no warnings. here is the output

Iter     Function value   Gradient norm 
     0     5.080082e+03     2.657559e+01
 * time: 0.02542591094970703
     1     5.079981e+03     2.004248e+01
 * time: 149.61270904541016
     2     5.079961e+03     1.497125e+01
 * time: 293.2913498878479
     3     5.079924e+03     1.386949e+01
 * time: 404.4286630153656
     4     5.079919e+03     1.275754e+01
 * time: 519.6313679218292
     5     5.079840e+03     4.859565e+00
 * time: 631.5725409984589
     6     5.079835e+03     3.599118e+00
 * time: 770.0869359970093
     7     5.079796e+03     1.848765e+00
 * time: 882.0380258560181
     8     5.079784e+03     1.772230e+00
 * time: 986.7223229408264
     9     5.079773e+03     7.275160e-01
 * time: 1067.3959460258484
    10     5.079765e+03     8.293510e-01
 * time: 1146.2089738845825
    11     5.079762e+03     1.422620e-01
 * time: 1223.3514399528503
    12     5.079762e+03     2.062762e-02
 * time: 1297.7948999404907
    13     5.079762e+03     2.165612e-03
 * time: 1366.6582679748535
    14     5.079762e+03     1.802472e-03
 * time: 1433.9624688625336
    15     5.079762e+03     3.306187e-03
 * time: 1499.6750829219818
    16     5.079762e+03     3.313480e-03
 * time: 1578.7967178821564
    17     5.079762e+03     3.667299e-03
 * time: 1661.0921380519867
    18     5.079762e+03     3.121457e-03
 * time: 1731.8161239624023
    19     5.079762e+03     3.241176e-03
 * time: 1805.8876328468323
    20     5.079762e+03     3.255183e-03
 * time: 1882.551826953888
    21     5.079762e+03     3.278371e-03
 * time: 2026.176521062851
    22     5.079762e+03     3.269786e-03
 * time: 2173.9755730628967
    23     5.079762e+03     3.274075e-03
 * time: 2320.8510229587555
    24     5.079762e+03     3.277968e-03
 * time: 2469.7986998558044
    25     5.079762e+03     3.278351e-03
 * time: 2620.940274953842
    26     5.079762e+03     3.282005e-03
 * time: 2767.507360935211
    27     5.079762e+03     3.285948e-03
 * time: 2915.770865917206
    28     5.079762e+03     3.290329e-03
 * time: 3069.461163043976
    29     5.079762e+03     3.286230e-03
 * time: 3169.5120148658752
    30     5.079762e+03     3.286927e-03
 * time: 3299.151221036911
    31     5.079762e+03     3.287002e-03
 * time: 3405.686693906784
    32     5.079762e+03     3.287002e-03
 * time: 3466.962636947632
FittedPumasModel

Successful minimization:                      true

Likelihood approximation:               Pumas.FOCE
Log-likelihood value:                   -5079.7618
Number of subjects:                            405
Number of parameters:         Fixed      Optimized
                                  0             10
Observation records:         Active        Missing
    ANC:                       2274              0
    Total:                     2274              0

---------------------------
                Estimate
---------------------------
tvPOP_CIRC0      6.2787
tvPOP_MTT      143.71
tvPOP_GAMMA      0.19585
tvPOP_SLOP       5.8194
tvPOP_SLOPC      0.0058817
Ω_1₁,₁           0.23317
Ω_1₂,₂           0.031576
Ω_1₃,₃           0.11131
Ω_2₁,₁           3.3201
σ_prop           0.36922
---------------------------

And this is the output of infer function:

symptotic inference results using sandwich estimator

Successful minimization:                      true

Likelihood approximation:               Pumas.FOCE
Log-likelihood value:                   -5079.7618
Number of subjects:                            405
Number of parameters:         Fixed      Optimized
                                  0             10
Observation records:         Active        Missing
    ANC:                       2274              0
    Total:                     2274              0

---------------------------------------------------------------------------
                Estimate            SE                     95.0% C.I.
---------------------------------------------------------------------------
tvPOP_CIRC0      6.2787           0.18622        [  5.9137   ;   6.6437  ]
tvPOP_MTT      143.71             4.2255         [135.43     ; 151.99    ]
tvPOP_GAMMA      0.19585          0.011701       [  0.17291  ;   0.21878 ]
tvPOP_SLOP       5.8194           0.2963         [  5.2386   ;   6.4001  ]
tvPOP_SLOPC      0.0058817        0.0020094      [  0.0019434;   0.00982 ]
Ω_1₁,₁           0.23317          0.024729       [  0.1847   ;   0.28164 ]
Ω_1₂,₂           0.031576         0.0083073      [  0.015294 ;   0.047858]
Ω_1₃,₃           0.11131          0.022134       [  0.067931 ;   0.15469 ]
Ω_2₁,₁           3.3201           0.9243         [  1.5085   ;   5.1317  ]
σ_prop           0.36922          0.01312        [  0.34351  ;   0.39494 ]
---------------------------------------------------------------------------