If I run the library for 'quantreg', I get a warning that backsolve is masked from base. Then I try to run a quantile regression and I get an error involving backsolve. How can I solve this?

library(quantreg)

Loading required package: SparseM

Attaching package: ‘SparseM’

The following object is masked from ‘package:base’: backsolve

quantile_mod1<- rq(X ~ Y, tau=0.3,data=mydata)

Warning message: In rq.fit.br(x, y, tau = tau, ...) : Solution may be nonunique

summary(quantile_mod1)

Error in base::backsolve(r, x, k = k, upper.tri = upper.tri, transpose = transpose, : singular matrix in 'backsolve'. First zero in diagonal [41] In addition: Warning message: In summary.rq(quantile_mod1) : 12506 non-positive fis