dosresmeta - Error on restricted cubic spline modeling

I see, so is it a limitation of the dosresmeta package?

I think Stata's glst command computes study-specific non-linear slopes and combines them at the end; so the number of non-referent obs does not matter as long as it is >2 obs...

I am referring to the dose-response meta-analysis tutorial in Stata by Shim et al.

Reference: Shim SR, Shin IS, Yoon BH, Bae J-M. Dose-response meta-analysis using STATA software. J Health Info Stat. 2016;41(3):351-8

Is there any alternative to solve this matter?

Thank you very much

Best,