“Subscript must be real positive integers or logicals” when using dsolve

It is necessary to plot the function, but after the function:

>> dsolve('U+0.15*10^(-6)*(22*10^3+0.27*10^3)*DU=0','U(0)=1') 

Gives an error message:

??? Subscript indices must either be real positive integers or logicals.

Error in ==> dsolve at 202

indx (isalphanumunder (eq_str (indx-1)) | isalphanumunder (eq_str (indx-1))) = [];