Calculating the likelihood for the same parameter vector gives some times HotRegion.RayError and sometimes not. For example, for a PSTU model with these parameters:
ray_error_vectors = np.array([[1.3728983226417986, 9.582564795756147, -0.7370097897513533, 0.020341921535536933, 0.2446314271154956, 0.3085074478486652, 6.161726551051954, 0.2722385280880412, 0.1088424612562043, 0.09511118603417756, -0.20397333010845675, 0.2730089443679007, 0.07205267520343456, 6.268835877470614, 0.13892737773308714, 0.13929302462200066, -0.6673219825864303, 43.29572745711499, 0.15926106535697776],
[1.3948493394100352, 9.885809466634319, -0.7378059269623075, 0.05209046240242854, 0.26593829571027794, 0.30030074135308593, 6.152591362014215, 0.3028962567969266, 0.11189861364104065, 0.3163235156902475, -0.18090198671715718, 0.37831814486006277, 0.08062299887788903, 6.2837707690528735, 0.301823322227404, 0.0734556127347533, 0.038060242003100875, 38.12674267246425, 0.069950983677363],
[1.4504741349215766, 9.964345293695063, -0.7376990825030287, 0.05231077261958955, 0.3125101665396582, 0.2883310085055355, 6.158536076365398, 0.34929965040108363, 0.13922416746314772, 0.3762910953045031, -0.1088833839030095, 0.3674370534557028, 0.0848153341067613, 6.283365299456526, 0.3277296346681094, 0.0789335506650999, 0.041164067903278756, 37.2022470540444, 0.3727061914382968],
[1.4735528282275252, 10.457830123791124, -0.7378484123368936, 0.037355529918352504, 0.2547006433955337, 0.3008791197170953, 6.1422486708067865, 0.3235375223078834, 0.06800264510371007, 0.26410349603068184, -0.1617038746390121, 0.4311675329816908, 0.0760231439178584, 6.3105097093930915, 0.45160313303673505, 0.14061958460494817, -0.2384724243174104, 40.67103216913422, 0.20448222807910185],
[1.4453407814357084, 10.146908699569305, -0.7368584267910054, 0.01964990147236456, 0.22389466926492813, 0.2901036575777484, 6.150388714872136, 0.24173029249541889, 0.031621557419247805, 0.12143903156214009, -0.04059643374757979, 0.3656508672709845, 0.07111131914906119, 6.2705901096745595, 0.25249421901181035, 0.25049555313159316, 0.8213846079640836, 37.201743090809224, 0.3557169757535461],
[1.3808755265352752, 9.938472600055215, -0.7373234241292637, 0.038090695714808, 0.20848955924558116, 0.3499019345952415, 6.137333628849363, 0.20874685687808478, 0.015647339958144758, 0.18401562094411084, -0.11270699145789095, 0.5151704479477742, 0.11024561408704435, 6.207609711463972, 0.4635566755582748, 0.04336617468826924, -0.08501577607156287, 39.77586219175194, 0.2241197817497454],
[1.3939678263044752, 10.032643585858235, -0.7378686469911245, -0.008163823813762433, 0.18064468998438807, 0.35549933794118727, 6.158157479592278, 0.1959883903008687, 0.05891540075708436, -0.18799746415470875, -0.09159001768682726, 0.39206722407268807, 0.05405417660686076, 6.33900627520628, 0.39021235725694337, 0.037841463115627395, 0.006661094136515722, 37.83603814467343, 0.14214428958513572],
[1.3882997991500199, 9.530617629629507, -0.7371227044400374, 0.0339982038930266, 0.2510280096822779, 0.2858787658417807, 6.160714815084994, 0.3135805766607258, 0.03732686055281593, 0.19705566106299255, -0.12764572477705569, 0.27824366870387945, 0.07300049378676185, 6.256549164904389, 0.261062611172553, 0.030864253237076814, -0.06273794537905707, 40.3896846420874, 0.1933777121353478],
[1.3963648946694658, 9.75180918818749, -0.7376789256868118, 0.04657606046523677, 0.207873337295747, 0.3197216371519362, 6.155871691557279, 0.2269811867788805, 0.0673456883838116, 0.10725984535658561, -0.08261332530872764, 0.24761442522190863, 0.0659951064231678, 6.260923369555037, 0.2477448120085302, 0.011670327376688053, 0.02494415987022336, 40.511153231310246, 0.10846480606826205],
[1.4186702446539952, 9.953520353284203, -0.737648320356077, 0.07808284376855712, 0.18872314542308272, 0.3185394382070733, 6.162273568477383, 0.3183941063273488, 0.06616832902059701, 0.1514926906332965, -0.11957389421224227, 0.4796207326694473, 0.06235653566369398, 6.321227088580457, 0.49361428099559557, 0.10689112819233139, -0.22389994753446957, 36.6482731608843, 0.14938838767845405],
[1.3787010362420065, 9.361996320671075, -0.7368516812337672, 0.035454524245767005, 0.26905101733036024, 0.24193662028865287, 6.177181907420643, 0.3300817447295375, 0.07238385399488184, 0.15105870445248648, -0.09711872283124207, 0.4993698858554692, 0.059190573473550376, 6.314681233490582, 0.4593524534164035, 0.11248086924505983, 0.27511595104407505, 40.56730410570455, 0.03656999657941817],
[1.3580021420080053, 9.322915124718374, -0.7368940262436027, 0.05492921076747426, 0.2348390891127287, 0.2857530623058969, 6.146885871788459, 0.34170106843859654, 0.05275083240658456, 0.12918683319018243, -0.048489812906943736, 0.440667075592995, 0.11308490624596565, 6.231901481614595, 0.4176169942397346, 0.16327455479758568, 0.2525615807538353, 43.08538477871486, 0.5053992005980066],
[1.4641891149190578, 9.753688831797174, -0.7379197878414928, 0.10009347169472876, 0.2871607970622169, 0.25477457029082534, 6.167602616866395, 0.3199608797521209, 0.10078890745658649, 0.4656943799322155, -0.1773768732856713, 0.31327972739655935, 0.11314131130604736, 6.268509044716219, 0.3526694912213938, 0.09356834407584315, -0.036039379591684614, 46.47057812181873, 0.4128718649157406],
[1.4030865876511545, 10.12386582429333, -0.737301463289495, 0.060689120323593915, 0.16473204546284323, 0.3270277317527089, 6.154129856639079, 0.18337297900801677, 0.0643035953633014, 0.3941169148887802, -0.06651607914796773, 0.3863107336992121, 0.0773954202891921, 6.219636265014224, 0.47415701705156127, 0.076670263099481, 0.11962485685015434, 39.43114795339812, 0.11528196288117881],
[1.3908219733986031, 10.165977977664983, -0.736994799173803, 0.04626243665486435, 0.19673301181783043, 0.36558995502760305, 6.136186399671636, 0.20813324506389438, 0.07967659181739094, 0.19080401977302675, -0.14582367711583719, 0.4959518942072795, 0.06270823319393146, 6.261927632333782, 0.48955272992646537, 0.05703423717565083, -0.06418005965328531, 43.87327156688406, 0.3836933338966083]])
-37043.9913545
-36497.1396261
-39029.1026809
Warning: HotRegion.RayError raised.
Parameter vector: [1.4735528282275252, 10.457830123791124, -0.7378484123368936, 0.037355529918352504, 0.2547006433955337, 0.3008791197170953, 6.1422486708067865, 0.3235375223078834, 0.06800264510371007, 0.26410349603068184, -0.1617038746390121, 0.4311675329816908, 0.0760231439178584, 6.3105097093930915, 0.45160313303673505, 0.14061958460494817, -0.2384724243174104, 40.67103216913422, 0.20448222807910185]
[-7.94188579e+89]
-36899.6237636
-42989.1700518
-36036.5098474
-36707.4067268
Warning: HotRegion.RayError raised.
Parameter vector: [1.3963648946694658, 9.75180918818749, -0.7376789256868118, 0.04657606046523677, 0.207873337295747, 0.3197216371519362, 6.155871691557279, 0.2269811867788805, 0.0673456883838116, 0.10725984535658561, -0.08261332530872764, 0.24761442522190863, 0.0659951064231678, 6.260923369555037, 0.2477448120085302, 0.011670327376688053, 0.02494415987022336, 40.511153231310246, 0.10846480606826205]
[-1.18676754e+89]
-40798.7330209
-38633.244213
-37748.5032624
-39338.9084573
Warning: HotRegion.RayError raised.
Parameter vector: [1.4030865876511545, 10.12386582429333, -0.737301463289495, 0.060689120323593915, 0.16473204546284323, 0.3270277317527089, 6.154129856639079, 0.18337297900801677, 0.0643035953633014, 0.3941169148887802, -0.06651607914796773, 0.3863107336992121, 0.0773954202891921, 6.219636265014224, 0.47415701705156127, 0.076670263099481, 0.11962485685015434, 39.43114795339812, 0.11528196288117881]
[-6.70283411e+89]
-36202.9432183
-37043.9913545
-36497.1396261
-39029.1026809
-36787.4490869
-36899.6237636
-42989.1700518
-36036.5098474
-36707.4067268
-36368.6065683
Warning: HotRegion.RayError raised.
Parameter vector: [1.4186702446539952, 9.953520353284203, -0.737648320356077, 0.07808284376855712, 0.18872314542308272, 0.3185394382070733, 6.162273568477383, 0.3183941063273488, 0.06616832902059701, 0.1514926906332965, -0.11957389421224227, 0.4796207326694473, 0.06235653566369398, 6.321227088580457, 0.49361428099559557, 0.10689112819233139, -0.22389994753446957, 36.6482731608843, 0.14938838767845405]
[-7.73923494e+89]
-38633.244213
-37748.5032624
-39338.9084573
Warning: HotRegion.RayError raised.
Parameter vector: [1.4030865876511545, 10.12386582429333, -0.737301463289495, 0.060689120323593915, 0.16473204546284323, 0.3270277317527089, 6.154129856639079, 0.18337297900801677, 0.0643035953633014, 0.3941169148887802, -0.06651607914796773, 0.3863107336992121, 0.0773954202891921, 6.219636265014224, 0.47415701705156127, 0.076670263099481, 0.11962485685015434, 39.43114795339812, 0.11528196288117881]
[-5.48656311e+89]
-36202.9432183